Erosion and Sediment Control

Transcription

Geovic Cameroon PLC
Nkamouna Project
Environmental and Social Assessment
Erosion and Sediment Control Plan
April 29, 2011
prepared for:
Geovic Cameroon PLC
Rue 1,793
BP 11555 Yaoundé Cameroon
Telephone: + 237 22 21 4518
Facsimile: + 237 22 21 1802
prepared by:
Knight Piésold and Co.
1580 Lincoln Street, Suite 1000
Denver, Colorado 80203-1512 USA
Telephone: (303) 629-8788
Facsimile: (303) 629-8789
E-mail: [email protected]
KP Project No. DV302.00009.13
KP Doc. No. DV-11-0265
Rev. No.
Date
Description
Knight Piésold
Client
0
April 29, 2011
Issued in Final
Jaye Pickarts
Roger Kouokam
Geovic Cameroon PLC
Nkamouna Project
Table of Contents
Page
Section 1.0 - Introduction .......................................................................................... 1-1 1.1 1.2 1.3 1.4 1.5 1.6 Background ................................................................................................................................... 1-1 Design Features ............................................................................................................................ 1-1 SEDCAD Modeling Results ........................................................................................................ 1-2 Construction Cost.......................................................................................................................... 1-2 Limitations and Disclaimer ............................................................................................................ 1-3 Contributors and Contacts ............................................................................................................ 1-3 Section 2.0 - Project Description .............................................................................. 2-1 2.1 2.2 Background ................................................................................................................................... 2-1 Facilities Descriptions ................................................................................................................... 2-1 2.2.1 Mine Panels ...................................................................................................................... 2-1 2.2.2 Ore Stockpiles................................................................................................................... 2-1 2.2.3 Haul and Access Roads ................................................................................................... 2-1 2.2.4 Plant Site........................................................................................................................... 2-1 2.2.5 Waste Fill Stockpile .......................................................................................................... 2-2 2.2.6 Reclaimed Mine Box Cuts ................................................................................................ 2-2 Section 3.0 - Design Approach ................................................................................. 3-1 3.1 3.2 3.3 3.4 3.5 Sizing of Sediment Control Structures .......................................................................................... 3-1 Sizing of Channels and Culverts ................................................................................................... 3-2 Sediment Pond/Rock Check Dam Sediment Trap Design Elements ........................................... 3-2 3.3.1 Sediment Ponds ............................................................................................................... 3-3 3.3.2 Rock Check Dam Sediment Traps ................................................................................... 3-3 Cleanout of Sediment Ponds and Rock Check Dam Sediment Traps ......................................... 3-4 Waste Fill Stockpile and Mine Box Cuts ....................................................................................... 3-4 3.5.1 Waste Fill Stockpile .......................................................................................................... 3-4 3.5.2 Initial Mine Box Cuts ......................................................................................................... 3-4 Section 4.0 - Hydrologic and Sedimentation Estimates .......................................... 4-1 4.1 4.2 Hydrology and Climatology ........................................................................................................... 4-1 4.1.1 Drainage Basins ............................................................................................................... 4-1 4.1.2 Time of Concentration ...................................................................................................... 4-2 4.1.3 Runoff Curve Numbers ..................................................................................................... 4-2 Sedimentology .............................................................................................................................. 4-2 Section 5.0 - Erosion and Sediment Control Plan for Nkamouna .......................... 5-1 5.1 Plant Site Area .............................................................................................................................. 5-1 Erosion and Sediment Control Plan, Rev 0
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5.2 5.3 5.4 5.5 5.6 Ore Stockpiles ............................................................................................................................... 5-1 Haul and Access Roads ................................................................................................................ 5-1 Mine Box Cut Panels..................................................................................................................... 5-2 Waste Fill Stockpile ....................................................................................................................... 5-2 Analysis of Sediment Control Efficiency ....................................................................................... 5-2 Section 6.0 - Construction Cost Estimates .............................................................. 6-1 Section 7.0 - Recommended Erosion Control Practices......................................... 7-1 Section 8.0 - References ............................................................................................ 8-1 Section 9.0 - Acronyms and Abbreviations ............................................................. 9-1 Tables
Table 1.1
Table 1.2
Table 5.1
Table 5.2
Table 5.3
Table 5.4
Table 5.5
Table 5.6
Construction, Operations, and Maintenance Cost Summary
Construction Cost Estimate
Channel Design Results
Culvert Design Results
Sediment Pond Design Results
Rock Check Dam Sediment Trap Design Results
Approximate Sizes of Reclaimed Box Cuts by Year
Sediment Loading
Figures
Figure 2.1 Typical Pit Advance and Concurrent Reclamation
Figure 2.2 Typical Haul Road Cross-Section
Figure 4.1 Typical and Design Surface Soil Particle Size Distribution
Drawings
Drawing No.
Drawing 1
Drawing 2
Drawing 3
Drawing 4
Drawing 5
Drawing 6
Drawing 7
Rev No.
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0
0
0
0
0
0
Title
Erosion and Sediment Control Plan North of Main
Erosion and Sediment Control Plan Northern Limit
Typical Sections and Details – Sheet 1 of 4
Appendix A
Appendix B
Surface Soil Particle Size Distribution Data and Analyses
SEDCAD Computer Program Input and Output
B-1
SEDCAD Computer Program Input
B-2
SEDCAD Computer Program Output
Appendices
G:\302\00009.13\Deliverables\Reports Specs\ESAP\ESCP\Rev0\Text\ESCPText.doc
Erosion and Sediment Control Plan, Rev 0
ii
Geovic Cameroon PLC
Nkamouna Project
Section 1.0 - Introduction
1.1
Background
The Nkamouna Project (the Project) Erosion and Sediment Control Plan (ESCP) was developed to meet
the Equator Principles and International Finance Corporation (IFC) Performance Standards on Social and
Environmental Sustainability and associated guidelines. The ESCP addresses the sediment control
facilities for the life-of-mine (LOM) (2011 through 2037) and the planned concurrent reclamation by
Geovic Cameroon PLC (GeoCam).
Specifically, the ESCP describes the feasibility-level design for control of erosion and sediment discharge
at the Project site, as well as the design criteria and preliminary layouts and designs of sediment control
structures for construction. The feasibility-level design is based upon widely accepted, contemporary
methods of engineering analyses. Final design of ESCP facilities will be based upon further geotechnical
and hydrologic investigations, and on additional sedimentation characteristics of the Project site.
The primary objective in developing the ESCP for the Project is to reduce the production and transport of
sediment from land disturbance related to mining activities. These activities include:

Mine box cut areas

Ore stockpile areas

Haul roads on the mine site

Mill site

Waste pile

Related infrastructure
1.2
Design Features
Erosion and sediment control measures that were used in the design of the ESCP to achieve this
objective are described below.
Diversion channels are located upgradient of disturbed areas to limit runoff from undisturbed areas onto
disturbed areas and/or into sediment ponds. Channels are also located downgradient from disturbed
areas to collect runoff and sediment from these areas and to convey this sediment-laden runoff to
sediment ponds or other sediment control facilities. Channels are sized to convey runoff from the
25-year/24-hour storm event.
Culverts are located as necessary to convey runoff under road embankments and other infrastructure.
Culverts are sized to convey the 25-year/24-hour storm event without overtopping the road embankment
or other infrastructure.
Runoff from disturbed areas is directed to sediment ponds, rock check dam sediment traps, or managed
with other Best Management Practices (BMPs) such as silt fences or grass filter strips. Some runoff from
1-1
undisturbed areas also may be directed to sediment ponds, where excess pond capacity is available, or
where local topography and drainage patterns do not permit diversion around the ponds.
There will be two types of sediment ponds: (1) embankment sediment ponds which have engineered
earthfill embankments, perforated pipe risers with discharge culverts through the embankment, and
emergency spillways to prevent overtopping of the embankment during a storm event; and (2) rock check
dam sediment traps which are located within open channels, along haul roads, and at the toes of some
material storage embankments. Rock check dams must be cleaned of their accumulated sediment after
each storm event. These traps do not necessarily have perforated pipe risers, but may have riprap
spillways to prevent overtopping of the sediment trap during a storm event.
Sediment ponds and rock check dam sediment traps have been designed with adequate volume to
promote settling of suspended sediment. Perforated pipe risers, culverts, and spillways are used to
dewater the sediment ponds but leave behind a majority of the eroded sediment. Sediment ponds are
designed to completely store the sediment and runoff from the 2-year/24-hour storm event, and to safely
pass the runoff from the 25-year/24-hour storm event without overtopping the sediment pond
embankment. Rock check dam sediment traps are designed to store the sediment eroded during the
2-year/24-hour storm event but these traps must be cleaned after every storm event and will not store
excess water or sediment.
1.3
SEDCAD Modeling Results
Surface water hydrology and sedimentology were evaluated for this ESCP at the Nkamouna Project site
utilizing the Sediment, Erosion, Discharge by Computer Aided Design (SEDCAD) 4 (Warner, Schwab,
and Marshall, 1998) computer program. Inputs to this program include drainage basin runoff variables,
storm precipitation depth and distribution, eroded sediment gradations, and hydraulic facility (channel,
ponds, and culvert) geometries. This information was used to develop a feasibility-level sediment control
plan for the Project that includes the following sediment control structures:

Channels (10.2 kilometers [km]) divert storm runoff around disturbed areas (diversion channels) and
also collect sediment-laden water from disturbed areas and direct it to sediment ponds (collection
channels). These channels have a minimum bottom width of 3.7 meters (m) and range in depth from
0.54 to 1.85 meters (including freeboard).

Five culverts direct flow from undisturbed and disturbed areas beneath various infrastructure including
haul roads and access roads. The culverts range in diameter from 1,650 to 1,950 millimeters (mm).

Nine sediment ponds ranging in embankment height from 3 to 18 meters. The total capacity of these
sediment ponds is approximately 198,000 cubic meters (m3).

Thirty-four rock check dam sediment traps located in open channels, along haul roads, or at the toes of
material storage embankments. The total capacity of these sediment traps is approximately 1,360 m3.
The trap efficiencies of the sediment ponds and rock check dam sediment traps were analyzed by
comparing the sediment inflow and outflow sediment loads. The typical target for sediment pond and trap
efficiencies is 80 percent as measured by the difference in inflow minus outflow sediment load divided by
inflow sediment load.
1.4
Construction Cost
The estimated construction, operations, and maintenance cost of the erosion and sediment control
system presented in this report, including open channels, culverts, sediment ponds, and rock check dam
sediment traps is US$4.9 million. Tables 1.1 and 1.2 present the estimated costs for construction and
implementation of the erosion and sediment control measures described in this Plan.
1-2
Section 2.0 - Project Description
2.1
Background
Drawing Nos. 1 through 3 show the proposed Project layout. As part of the normal evolution of any
project, additional engineering continues until project commencement. The updated engineering designs,
as identified below, have resulted in certain improvements to increase efficiency in the Project
performance and improve the general layout and operating description. Drawing No. 1 also shows the
locations of physically upgraded (PUG) facility, counter-current decanting (CCD) facility, Glauber Salt
storage pad, the plant site, ore stockpiles, haul road locations, and the mine panels. Drawing Nos. 2
and 3 of the Project show the mine panels and haul roads to the north of the major facilities for the
Project.
2.2
Facilities Descriptions
2.2.1
Mine Panels
The current mine plan still envisions concurrent reclamation so that no more than 60 hectares of mine
panels would be open at any given time. Figure 2.1 shows the proposed typical pit advance and
concurrent reclamation for the Project. A result of this mining method is that overburden from the mine
panels will be stacked on the upgradient side of the box cuts and will not contribute runoff or sediment to
the environment (Personal Communication, Andrew Lovato, August 16, 2010). Therefore, sediment
control facilities for the box cut overburden are required only for the first reclaimed mine panel in each
yearly advance. Panels will be actively mined during years 2014 through 2024 as shown on Drawing
Nos. 1 through 3.
2.2.2
Ore Stockpiles
As shown on Drawing Nos. 1 and 2 there are 15 ore stockpiles located north and east of the plant site.
These stockpiles (Nkamouna, Emergency, and Mada) have a range of volumes from approximately
500,000 m3 to over 7,000,000 m3. These ore stockpiles are assumed to be disturbed for purposes of the
ESCP and the gradation of the materials on the surfaces of the ore stockpiles are assumed to be the
same as the surface soils described below, that is, Laterite soil textures. These stockpiles have a
combined footprint area of approximately 1,536,500 square meters (m2) (154 hectares).
2.2.3
Haul and Access Roads
Haul roads could be a major source of sediment during mining. The conceptual locations of the proposed
haul roads for the various mine panels by year are shown as straight lines (by GeoCam) on Drawing
Nos. 1 through 4. Figure 2.2 shows a typical haul road cross-section. Cut and fill slopes for the haul
roads were not supplied by GeoCam and these disturbances were not included in the erosion calculations
or the sediment control structures. The sediment from the haul roads will be controlled by the use of rock
check dam sediment traps on both sides of the haul road to account for the 2 percent cross-slope as
shown on Figure 2.2. The unit area (area per meter of haul road length) for each half of the typical haul
road is 23 m2 per meter (Figure 2.2). The spacing of rock check dam sediment traps should be
re-evaluated during haul road design.
2.2.4
Plant Site
The plant site pad is shown on Drawing No. 1 and has an approximate disturbed footprint area of
650,000 m2 (65 hectares). It was assumed that the total plant footprint would be disturbed over the LOM.
2-1
2.2.5
Waste Fill Stockpile
Approximately 3.6 million m3 of cut material at the Nkamouna mine site will be wasted during
construction. Whereas this material will come from various locations around the site, it will eventually be
placed in a waste fill stockpile somewhere in the Napene Creek catchment. This stockpile surface will be
reclaimed with native vegetation to control long-term erosion. Silt fences and fiber rolls will be used to
prevent erosion during initiation of vegetative growth.
2.2.6
Reclaimed Mine Box Cuts
As shown on Figure 2.1, concurrent reclamation will be conducted on the mine box cuts. It is assumed
that the initial box cut during each year will be reclaimed the following year. Future box cuts in the same
year will utilize the downgradient reclaimed box cut as a “grass filter” BMP for sediment control.
Therefore, a generic box cut BMP was designed utilizing silt fences in the first year of reclamation and
then assuming this reclaimed box cut will act as a grass filter in subsequent reclamation years for
upgradient reclaimed box cuts. Each first reclaimed box cut is assumed to have a typical unit area of
30 m2 per meter of box cut reclaimed length.
2-2
Section 3.0 - Design Approach
The primary objective in developing an ESCP for the Project is to reduce the production and transport of
sediment resulting from land disturbance related to mining activities. Operational goals for the control of
sediment production center on efforts to prevent erosion and keep eroded soil transport to a minimum.
Scheduling and sequencing of construction activities, concurrent reclamation, revegetation, and site
grading to control runoff quantity and velocity are important elements of the overall ESCP. Erosion
control strategies and practices are discussed in Section 7.0 of this report.
Development and operation of the open cut mine panels at the Project will result in areas of disturbance
that cannot be reclaimed or revegetated in the near term. The mine panels, overburden disposal areas,
roads, ponds, and related infrastructure will require comprehensive sediment control measures. With this
objective in mind, the following design goals were identified for development in the ESCP:

Sediment ponds and rock check dam sediment traps should be located as close to the sediment source
as practical to limit the volume of runoff and sediment that needs to be directed into the ponds or traps.

Diversion channels should be located upgradient from disturbed areas to collect and divert runoff from
these areas and discharge it to adjacent stream channels.

Collection channels should be located downgradient from disturbed areas and runoff from these areas
directed to sediment ponds and traps for sediment removal prior to discharge.

Structures should be designed to store the sediment volume associated with the selected design storm
and to safely pass storm runoff up to the selected extreme storm event.

Whenever practicable, sediment structure access roads should be located upgradient, within existing
areas of disturbance in order to limit the need to include additional sediment control related to access
road construction and maintenance.

The design of sediment control structures should include sufficient flexibility to allow for modifications
during field installation and operation. The installation of sediment control structures themselves
necessitates additional disturbances and increased erosion potential. Because of the limited
information available regarding the depths of unconsolidated site materials and local site topography,
field fitting and modifications to the designs of the structures may be warranted as more information is
gathered during construction.
To increase the overall efficiency of site sediment control, the following additional goals should be
incorporated into the construction and operation of the sediment control structures:

Construction of sediment control structures should be limited to the dry seasons (approximately
November through February) to reduce construction-related erosion and sediment transport.

The areal extent of disturbance should be minimized and, wherever practicable, the disturbed areas
reclaimed and revegetated prior to the onset of the next wet season (approximately March through
October).
3.1
Sizing of Sediment Control Structures
Sediment ponds and rock check dam sediment traps at the Project are designed to retain the potential
sediment load associated with surface disturbance resulting from mining, and where feasible, the
background sediment load for the basin of interest. Because the sediment control structures are seldom
ever 100 percent efficient, retention of some background sediment load usually makes the whole mine
site neutral in terms of its contribution of eroded sediment offsite. Design parameters for elements of the
sediment control system are discussed below.
3-1
3.2
Sizing of Channels and Culverts
Diversion channels are located upgradient from disturbed areas to limit runoff from these areas onto
disturbed areas and, consequently, into sediment ponds. Collection channels are located downgradient
from disturbed areas to collect runoff and sediment from these areas and convey this flow to the sediment
ponds and traps. The following guidelines were utilized to design the diversion and collection channels:

Channels are sized to pass the peak discharge from the 25-year/24-hour storm event.

Channels are trapezoidal in shape with a minimum bottom width of 3.7 meters (to allow dozer access)
and maximum sideslopes of 2H:1V (Horizontal:Vertical). When cut into steep topography or rock, a
steeper sideslope is used.

The maximum longitudinal channel slope is 10 percent.

Constructed channels on the mine site are lined with riprap as the lateritic soils in which the channels
will be constructed will easily erode under low flow velocities (typically about 1 m per second).
Alternative methods of channel protection such as grass-lining may be feasible if the longitudinal slope
is less than 3 percent. Riprap or grouted riprap also may be used if suitable rock materials are available
on site, as this may reduce construction costs.

Natural drainage-ways are assumed to be lined where utilized to convey diverted runoff from one
channel to a second channel or to a sediment pond.

Natural drainage channels are riprap lined downgradient of pond and culvert discharge points for
distance of 50 meters.
Culverts are located as necessary to convey water and sediment under road embankments or other
facilities. This includes discharges in natural channels as well as constructed channels. The following
guidelines were utilized to design culverts:

Culverts are sized to pass the 25-year/24-hour storm event without overtopping the associated
embankment.

A minimum of 2 m of fill is placed as cover on the culverts at road embankment crossings.

Culverts are designed of corrugated steel pipe.

Flow through the culverts is assumed to be governed by inlet conditions. Inlets are protected by
grouted riprap.

Plunge pool or grouted riprap energy dissipaters and downstream channel protection are assumed at
the discharge points from culverts.
3.3
Sediment Pond/Rock Check Dam Sediment Trap Design Elements
To trap sediments prior to discharge of water off site, runoff from disturbed areas is directed to sediment
ponds or traps. Additionally, runoff from undisturbed areas where erosion is occurring also may be
directed to sediment ponds or rock check dam sediment traps where excess capacity is available or
where the local topography and drainage patterns do not allow diversion.
The sediment ponds and rock check dam sediment traps are designed to include adequate volume to
promote settling. Perforated pipe risers and spillways are used in sediment ponds allowing for sufficient
capacity to store sediment as it settles from the water. Rock check dam sediment traps utilize
uncontrolled overflow spillways to provide capacity for sediment storage. Guidelines utilized for sizing
sediment ponds and traps are based on consideration of the storm event volumes versus dam safety as
described in the following sub-sections.
3-2
3.3.1
Sediment Ponds

Sediment ponds are designed to completely store the sediment and runoff from the 2-year/24-hour
storm event.

The ponds are designed to pass the runoff from the 25-year/24-hour storm event through pipe risers or
emergency spillways without overtopping the embankment.

Sediment ponds are designed with sufficient capacity to allow for adequate settling of the sediment.
Settling characteristics are based on the particle-size distribution of the site material obtained from insitu materials from test pits and test borings, and from overburden materials.

Sediment pond embankments have upstream and downstream slopes of 2.5H:1.0V and a minimum
crest width of 5 m.

The elevation of the top of the perforated pipe riser is based on the settled depth of the sediment from
the 2-year/24-hour storm event and is a minimum of 0.3 m above the sediment stage.

Sediment pond footprints will be cleared and grubbed and topsoil removed, stored and protected for
reclamation at this site and/or other sites.

A blanket drain and underdrain pipe system will be included to dissipate ground water pressure beneath
the embankment.

If the embankment is also used for water supply or water storage for an extended period of time, a filter
and drain downstream of the seal zone is needed that connects to the blanket drain.

Access to the sediment pond embankment areas is provided for maintenance of the spillway and for
sediment removal.

Sediment ponds will be routinely observed and maintained.

Sediment that accumulates in the pond will be excavated annually or when the sediment storage is onehalf the total storage.

Removed sediment will be relocated and stored in areas where it will not erode.
3.3.2
Rock Check Dam Sediment Traps

Sediment traps are designed to contain the water and sediment from the 2-year/24-hour storm event.

Trap should be sized to accommodate a settling zone and sediment storage zone with recommended
minimum volumes of 20 m3 and 10 m3/hectare of contributing drainage area, respectively. In many
cases, the size of an individual sediment trap is limited by available space. Multiple traps or additional
volume may be required to accommodate specific rainfall, soil, and site conditions.

Sediment traps may only be utilized where the drainage area is less than 2 hectares.

Sediment trap side slopes are 3H:1V or less.

Sediment traps have uncontrolled spillways designed to pass the peak flow from the 2-year/24-hour
storm event.

Riprap or vegetation is used to protect the trap outlets against scour.

The area under the embankment, as well as the pool area, must be cleared, grubbed, and stripped of
vegetation and root mat.

The fill material for the embankment must be free of roots or other woody vegetation as well as
oversized stones, rocks, organic material, or other objectionable material. Construction equipment may
be used to compact the embankment.

When an earth or stone outlet is used, its crest elevation should be at least 0.3 m below the top of the
embankment.

Access is provided for maintenance of the sediment trap.

Use of vegetation will be considered as an alternative to riprap as a sediment filtration medium.
3-3
3.4
Cleanout of Sediment Ponds and Rock Check Dam Sediment Traps
Sediment will need to be excavated from the sediment ponds and traps on an annual basis. This material
will be hauled to storage areas where it will be protected from surface erosion by wind, rainfall, and runoff.
Storage areas will be regraded to divert runoff around these stockpiles. If the sediment is stored through
the next wet season, the stockpiles will be covered or revegetated with fast-growing species to promote
surface stability and limit erosion. The implementation of planned concurrent reclamation at the site will
reduce the need for long-term stockpiles and the corresponding need for stockpile maintenance.
During development of the mine panels, overburden disposal areas, roads, ponds, and related
infrastructure, topsoil will be reclaimed, stored, and protected in a similar manner as the sediment.
Stockpiled topsoil will be used for concurrent reclamation and to support revegetation of disturbed areas.
Where needed, stockpiled sediment may be used for reclaiming disturbed areas and for construction of
low-permeability caps on overburden or tailings disposal areas.
Where possible, sediment and topsoil storage will be located near the sediment ponds or adjacent to or
within the overburden and tailings disposal areas to reduce haul distances when cleaning out the
sediment ponds and traps, and during reclamation and capping. These materials also can be stored on
top of overburden stockpiles when sufficient space is available.
3.5
Waste Fill Stockpile and Mine Box Cuts
3.5.1
For calculation of the cost to reclaim the waste fill stockpile, it is assumed that the stockpile would be
square with base dimensions of 615 m by 615 m, would be 10 m in height with 3H:1V sideslopes, and
have top dimensions of 585 m by 585 m. The critical reclamation time is during construction and
immediately after construction but prior to establishment of native vegetation to control erosion. The U.S.
Environmental Protection Agency (USEPA, 2010) provides design criteria, effectiveness results, and
estimated unit costs for erosion control BMPs. Review of the available erosion control BMPs for
reclaimed stockpile surfaces indicated that both silt fences and fiber rolls would be acceptable for
stockpile reclamation. Silt fences are more expensive but fewer are needed per down gradient length of
reclaimed slope. More fiber rolls are required per down gradient length but this erosion control BMP is
typically four times less expensive per foot of length than silt fences. Both of these BMPs were
considered for reclamation of the waste fill stockpile in the Napene Creek catchment. These BMPs would
only be used on the sideslopes of the stockpile, with the top erosion controlled only by vegetation at the
time of reclamation.
The design criteria for silt fences provides that the upgradient distance between silt fences should not be
more than 30 m (USEPA, 2010). For fiber rolls on a 3H:1V slope, the design criteria is one roll for every
10 m of up gradient distance. Detailed design and installation criteria for these two erosion control BMPs
can be found in USEPA (2010). Typical installation schematics for silt fences and fiber rolls are shown on
Drawing No. 7.
Given that the slope length for the stockpile along the 3H:1V slope is approximately 32 m, this translates
to 1 line of silt fence at the toe of the slope; and 3 lines of fiber rolls, one located at the toe of the slope
and the other two about 10 and 20 m up the slope, respectively.
The total length of 1 line of silt fence and 3 lines of fiber rolls was calculated from the geometry of the
stockpile. The results were that the perimeter length of silt fence was 2,460 m and the perimeter length of
fiber rolls was 7,280 m.
3.5.2
Initial Mine Box Cuts
For the mine box cut reclamation, silt fences are assumed for the first year of reclamation. After
vegetation is established in the first year, it is assumed that the box cut reclaimed area will behave as a
3-4
30-m wide grass filter strip for sediment control when the next up-gradient box cut is reclaimed. The
assumed slope of the typical box cut reclaimed area is 4 percent. Applying the same criteria to the 30-m
wide box cut reclamation results in various lengths of silt fence for each year of mining. In all cases, only
one silt fence at the toe of each first-year reclaimed box cut for each mine panel is required. Alternatively,
if fiber rolls are utilized, the distance between rolls on a 4 percent slope is greater than 30 m, and thus,
only one fiber roll at the toe of the reclaimed box cut is required.
3-5
Section 4.0 - Hydrologic and Sedimentation Estimates
4.1
Hydrology and Climatology
Discrete drainage subbasins are evaluated based on the relative locations of disturbed areas, the local
topography and drainage patterns, and the proposed locations of sediment control structures. The runoff
volume and peak discharge calculations for each drainage basin for the design storm events are
completed using SEDCAD 4 (Warner, Schwab and Marshall, 1998). This computer program develops
runoff hydrographs for design storm events for a series of drainage subbasins based on the input
drainage area, the time of concentration, and the Natural Resources Conservation Service (NRCS, 1985)
curve number (CN). A Type II storm curve is used to represent the rainfall distribution with time over the
duration of the storm event.
4.1.1
Drainage Basins
Drainage basin and subbasin areas, lengths, and slopes are estimated using a 2-meter contour map with
the proposed facilities superimposed on it. The locations of the Project facilities and the original 2-meter
contour map were provided by GeoCam. The proposed ESCP facilities are shown on these 2-meter
contour maps (Drawings 1 through 4).
The NRCS unit hydrograph methodology (NRCS, 1985) uses the lag time (in hours) as an input
parameter to compute the runoff hydrograph, where lag time is calculated as 0.6tc, where tc is defined as
the time from the center of mass of rainfall to the peak of the unit hydrograph. A Type II 24-hour
precipitation distribution and the 24-hour precipitation values for the 2-year and 25-year return periods are
used in the SEDCAD modeling to calculate the runoff volumes and peak discharges for these return
periods. Precipitation values are taken from the Nkamouna Project Preliminary Climatological Data
Analysis Report (Knight Piésold, 2007, updated in Knight Piésold, 2008) and are as presented in the
following table:
Summary of Design 24-Hour Precipitation Values for the Nkamouna Project
Return Period (years)
24-Hour Precipitation (mm)
2-year
130
10-year
253
25-year
318
100-year
415
Source: Knight Piésold (2007) as updated in Knight Piésold (2008).
Because of the short period of record used to calculate these design precipitation values, the upper
95 percent confidence interval values are used for the design precipitation values (Knight Piésold, 2008).
Additionally, the large depths of 24-hour rainfall calculated from a very short period of record (Knight
Piésold, 2008) results in very large structures. Therefore, the philosophy of designing for the more
frequent events (e.g. the 2-year storm event) is utilized to control these frequent events and still have
reasonably sized sediment control structures.
4-1
4.1.2
Time of Concentration
The NRCS lag equation is used to calculate the time of concentration for each subbasin. This equation
is:
tc = 0.0526L0.8[(1000/CN)-9]0.7
Y0.5
where, L = hydraulic length of watershed (longest flow path), feet
CN = NRCS runoff curve number
Y = average watershed slope, percent
tc = time of concentration in minutes
The time of concentration is defined as the time it takes water to flow from the hydraulically most remote
point in a basin to the basin outlet.
4.1.3
Runoff Curve Numbers
Due to the lateritic soils and underlying saprolites, the infiltration rates at the Project site are considered to
be low. Knight Piésold (2008) estimated an NRCS CNs for undisturbed surface conditions of 85. This
report adopts that same CN, and in addition the following CNs are estimated for other surface conditions:
Summary of Design NRCS Runoff Curve Numbers for the Nkamouna Project
Surface Condition
NRCS CN
Undisturbed
85
98
Disturbed
95
Source: Knight Piésold (2008).
4.2
Sedimentology
The sediment loads for each discrete subbasin are also calculated using the SEDCAD 4 model. For
storm-event sediment loads, the Modified Universal Soil Loss Equation (MUSLE) subroutine is utilized.
This method integrates the peak discharge and runoff volume for a given storm event into the Universal
Soil Loss Equation (USLE) to obtain storm-event sediment loads. Annual sediment yields are calculated
using the Revised Universal Soil Loss Equation (RUSLE as documented in Toy and Foster, 1998).
RUSLE is used as a pre-model to establish sedimentology input variables to SEDCAD prior to applying
the MUSLE sediment load method.
For the design of sediment control structures, SEDCAD requires the input of the eroded sediment
particle sizes. Because no eroded sediment particle size distributions are available at the Project site,
actual surface soil particle size distributions are used. These distributions are taken from the Nkamouna
Project Napene Creek Tailing Storage Facility, NCTSF Stage 1 West Dam Final Design Report (Knight
Piésold, 2008) and are assumed to be representative of the entire Project site. Typical surface soil
particle size distributions for individual samples are shown and tabulated in Appendix A and are plotted
on Figure 4.1. The average (mean) distribution tabulated as follows:
4-2
Mean Particle Size Distribution Used in the SEDCAD 4 Model(1)
Median Diameter (mm)
Percent Passing
9.52
100.0
4.76
99.8
2.00
94.8
0.84
89.0
0.42
85.2
0.246
80.6
0.149
75.9
0.074
71.0
0.0458
70.0
0.0330
67.8
0.0212
65.1
0.0153
62.7
0.0093
58.3
0.0044
53.3
0.0023
48.0
0.0010
44.5
(1) Mean of Upper Laterite samples from test pits (see Figure 4.1 and Appendix A).
Water and sediment routing, sizing and design of the sediment control structures, sizing and design of
culverts, and outlet and channel protection are determined using SEDCAD 4. Elevation-area-capacity
curves for the sediment ponds and rock check dam sediment traps are estimated directly from the
2-meter contour maps provided by GeoCam.
Input hydrology and sedimentology data for the SEDCAD 4 program is included in Appendix B-1.
Outputs from the SEDCAD computer program are attached for the diversion and collection channels,
the sediment ponds, the culverts, the generic rock check dam sediment traps, and the generic box cut
reclamation in Appendix B-2.
4-3
Section 5.0 - Erosion and Sediment Control Plan for Nkamouna
The ESCP for the Project site is presented on Drawing Nos. 1 through 3. The main sediment control
structures contained in the Plan include a series of connected channels, culverts, sediment ponds, rock
check dam sediment traps, and first reclamation mine panel box cut BMPs.
Channels are designated as D1 through D3 for diversion channels, and C1 through C7 for collection
channels on the drawings, and their design results are summarized in Table 5.1. A typical channel cross
section is shown on Drawing 5. Culverts are used to direct discharge under roadways and into natural
drainage channels. Culverts are designated as V1 through V5 on the drawings and their design details
are summarized in Table 5.2.
Sediment ponds are designated on the drawings as S1 through S9 and their capacities and other design
details are summarized in Table 5.3. Other sediment control facilities such as rock check dam sediment
traps are generically designated as T, and their design details are summarized in Table 5.4. The
generically designated first reclamation box cut BMPs are summarized by year in Table 5.5. Typical
sections and construction details of these sediment control structures are shown on the drawing details
(Drawing Nos. 4 through 7). Diversion channels have already been designed for the PUG facility and the
results of this design can be obtained from the report entitled Nkamouna Project, Napene Creek Tailing
Storage Facility, NCTSF Stage 1 West Dam Final Design Report (Knight Piésold, 2008). The ESCP was
developed for each major Project area as described below.
5.1
Plant Site Area
Sediment control structures associated with the plant site area are shown on Drawing Nos. 1 and 2. The
Plan includes the following elements for the plant site area: a diversion channel (D3) to route runoff from
undisturbed areas around the plant, collection channels (C4 and C5) to transport runoff from disturbed
plant site areas to a sediment pond (S1), and a series of culverts to pass runoff beneath the haul roads.
A sedimentation pond (S1) is located downgradient of the plant site. Captured sediment will be allowed
to settle out before runoff is discharged. Structure details for these facilities are shown on Drawing
Nos. 4 through 7.
5.2
Ore Stockpiles
Sediment control structures for the Nkamouna, Emergency, and Mada ore stockpile areas are also shown
on Drawing Nos. 1 and 2. The Plan includes the following elements for the ore stockpiles: two diversion
channels (D1 and D2) to route runoff from undisturbed areas around the ore stockpiles, collection
channels (C1, C2, C3, C6, and C7) to transport runoff from disturbed ore stockpile areas to the nine
sediment ponds. Nine sediment ponds (S2, S3, S4, S5, S6, S7, S8, and S9) are located downgradient of
the ore stockpiles. Captured sediment will be allowed to settle out before runoff is discharged. Structure
details for these facilities are shown on Drawing Nos. 4 through 7.
5.3
Sediment control structures associated with the haul and access roads are shown on Drawing Nos. 1
through 3. Generic rock check dam sediment traps are spaced at approximately every 870 meters on
both sides of the road. These traps will collect sediment from the top and sideslopes of the haul roads,
reducing the sediment load to the environment and reducing the flow velocity in the roadside channels.
Reducing channel flow velocity further minimizes erosion. Rock check dam sediment traps will be
cleaned out after each storm event. A typical design for a rock dam sediment trap is shown on Drawing
No. 6.
5-1
5.4
Mine Box Cut Panels
The box cut surface will be reclaimed with native vegetation to control long-term erosion. A combination
of hydroseeding and the use of silt fences and fiber rolls will be used to minimize short term (one year or
less) erosion potential.
BMP erosion control facilities are designed for the first reclaimed box cut for each mine panel to minimize
sediment discharge after reclamation. The concept is to utilize silt fencing or fiber rolls at the toe of each
reclaimed box cut in each mine panel. The approximate lengths of silt fence, or alternatively fiber roll, by
year are shown in Table 5.5. A typical silt fence BMP design is shown on Drawing No. 7.
After one year of vegetation growth, the reclaimed box cut will serve as a grass buffer strip to capture
sediment from future upgradient box cuts at the same mine panel. A typical grass buffer strip design is
also shown on Drawing No. 7.
5.5
Waste material from mine construction will be placed in a waste fill stockpile at a location to be
determined within the Napene Creek catchment. The stockpile surface will be reclaimed with native
vegetation to control long-term erosion. A combination of hydroseeding and the use of silt fences and
fiber rolls will be used to minimize short term erosion potential.
5.6
Analysis of Sediment Control Efficiency
The sediment pond and rock check dam sediment trap designs are based on the hydrology and
sedimentology characteristics of the associated drainage basins, the calculated sediment yields for the
2-year and 25-year/24-hour storm event water volumes, and the sediment loads for the various basins.
The design sediment loads for storm events are computed using the SEDCAD 4 model. The sediment
loads into and out of the sediment control structures are summarized in Table 5.6 along with the trap
efficiency for each BMP. The minimum sediment trap efficiency for all sediment control structures was
9.1 percent, and the maximum efficiency was 62.0 percent.
5-2
Section 6.0 - Construction Cost Estimates
Based on the designs presented on the Drawings, the construction, operations, and maintenance cost of
the sediment control structures on the Project site is approximately US$4.9 million. A summary of these
construction costs is presented in Table 1.1. Cost for additional sediment control structures such as
roadside rock check dam sediment traps, rock fill drains, or additional channel protection past the
50-meter design limit downstream from structure discharge points are not included in this estimate.
Construction costs for the sediment control structures are estimated based on the designs shown on the
Drawings in this report. The estimated quantities and unit costs for each cost item are listed in
Table 1.2 and are based on vendor quotes, Knight Piésold’s previous work similar to the project, or by the
client. The unit rates have been adjusted, as deemed necessary, to account for site and project-specific
conditions. Generally, the unit rates for earthwork are based on borrow sources and stockpiles used in
the construction process that are located in the vicinity of the sediment control structures. No overall
contingency costs have been included in the cost estimate to avoid duplication of overall project
contingencies that may be added.
Unit rates are inclusive of equipment, operator, and material costs unless otherwise noted in Table 1.2.
Mobilization and demobilization costs and indirect costs also have been included in the estimates. The
following items are included with indirect costs: engineering effort to develop final designs; field
investigations and laboratory testing programs to support the final design effort; construction drawings,
specifications and bid documents; technical oversight and construction quality control and quality
assurance for construction of the facility; surveying for facility layouts; and the construction report and “asbuilt” drawings.
For purposes of this cost estimate, indirect costs (engineering design,
mobilization/demobilization, etc.) are estimated as 10 percent of the construction (direct) costs as shown
in Table 1.2.
6-1
Section 7.0 - Recommended Erosion Control Practices
In conjunction with the sediment control structures described in the previous sections, additional erosion
control practices will be considered for implementation at the Project site to limit the extent and severity
of erosion related to disturbances as a result of mining activities. Suggested additional erosion control
practices follow:

Protecting natural drainage channels downstream from sediment ponds and discharge points using rock
check dam sediment traps. The installation of channel protection will aid in dissipating the energy of
high discharges and may reduce channel bed and bank scour related to these high flows or increased
flows due to drainage basin changes during mining.

Implementing rapid stabilization of disturbed areas to reduce erosion and sediment transport. Practices
such as the application of organic mulches, erosion mats, and chemical stabilizers on disturbed
surfaces (especially slopes) may increase the efficiency of revegetation.

Discouraging local agricultural practices such as “slash and burn” in order to promote the development
of a healthy vegetative cover on undisturbed areas. Destruction of vegetative cover results in
decreased surface stability, reduced infiltration rates, and increased runoff and sediment yields.

Implementing physical methods of soil stabilization, especially on steep slopes. Practices such as
surface roughening (scarification), use of silt fences, cross-slope barriers (fiber rolls, wattles or brush),
and use of surface mats have all been shown to be successful and effective in reducing erosion and
sediment transport from disturbed surfaces.

Recovering soil from the mine panels, the overburden disposal areas, and the sediment pond areas
during construction and stockpiling this soil for future reclamation. This practice should be used in
conjunction with the establishment of a short-term vegetative cover consisting of fast-growing plant
species to protect against erosion. Attempting to establish a vegetative cover prior to the onset of the
next wet season will help prevent excessive erosion and sediment transport. Implementing physical
methods of surface stabilization and containment of overburden stockpiles should be considered if
revegetation proves ineffective.

Implementing rapid revegetation of disturbed areas such as embankment fill slopes and waste
stockpiles. Utilizing local vegetation species that grow rapidly in order to maximize the development of
a self-sustaining vegetative cover is important. A vegetative cover protects the surface against erosion
and is a successful long-term stabilization method.

Maintaining reclaimed areas for several years after reclamation or until long-term surface stabilization is
achieved. Annual maintenance may include repairing and revegetating erosional features (rills and
gullies) that develop on newly reclaimed slopes. The addition of channel protection in natural drainageways located downgradient from sediment control facilities may be needed if channel scour is present.
7-1
Section 8.0 - References
Knight Piésold and Co., 2007, Preliminary Climatological Data Analysis, Technical Memorandum, May 23.
Knight Piésold and Co., 2008, Nkamouna Project, Napene Creek Tailing Storage Facility, NCTSF Stage 1
West Dam Final Design Report, August 22.
Knight Piésold and Co., 2010, Geovic Cameroon, PLC, Nkamouna Project, Environmental and Social
Assessment, 2010 Update, March 31.
Natural Resources Conservation Service (NRCS), 1985, National Engineering Handbook–Section 4–
Hydrology, Washington, D.C., U.S. Department of Agriculture.
Toy, T.J. and G.R. Foster, 1998, Guidelines for the Use of the Revised Universal Soil Loss Equation
(RUSLE) Version 1.06 on Mined Lands, Construction Sites, and Reclaimed Lands, August, Denver,
Colorado, Office of Surface Mining, U.S. Department of the Interior.
U.S. Environmental Protection Agency (USEPA), 2010, National Pollutant Discharge Elimination System
(NPDES), Construction Site Stormwater Runoff Control, http://cfpub.epa.gov/npdes/, May 28.
Warner, R.C., P.J. Schwab, and D.J. Marshall, 1998, SEDCAD™ 4, Design Manual and User’s Guide,
Ames, IA, Civil Software Design, August, 126 p.
8-1
Section 9.0 - Acronyms and Abbreviations
BMP
CCD
CN
CN
ESCP
GeoCam
IFC
km
Knight Piésold
LOM
m
m2
m3
mm
MUSLE
NRCS
Project
PUG
RUSLE
SEDCAD
USEPA
USLE
Best Management Practice
counter-current decanting
curve number
curve number
Geovic Cameroon PLC
International Finance Corporation
kilometer
Knight Piésold and Co.
life-of-mine
meter
square meters
cubic meters
millimeters
Modified Universal Soil Loss Equation
Natural Resources Conservation Service
Nkamouna Project
physically upgraded
Revised Universal Soil Loss Equation
Sediment, Erosion, Discharge by Computer Aided Design
United States Environmental Protection Agency
Universal Soil Loss Equation
9-1
Tables
Figures
Drawings
Appendix A
Surface Soil Particle Size Distribution
and Analyses
Particle Size Distributions for
Upper Laterite Soil Samples
Particle Size Distribution Analyses
Appendix B
SEDCAD Computer Program Input and Output
B-1 SEDCAD Computer Program Input
B-2 SEDCAD Computer Program Output
Appendix B-1
SEDCAD Computer Program Input
Appendix B-2
SEDCAD Computer Program Input
SEDCAD 4 for Windows
Copyright 1998 -2010 Pamela J. Schwab
Civil Software Design, LLC
1
Nkamouna ESCP
Sediment Pond S1 (With Emerg. Splwy), Diversion Channels D1
and D3 Plant Site
J. Kunkel
Knight Piesold
Filename: S1YD1D3System.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Particle Size Distribution:
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Structure Networking:
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Musk. X
Description
Channel
#1
==>
#4
0.000
0.000 Collection Channel C4
Channel
#2
==>
#4
0.000
Pond
#4
==>
#6
0.000
0.000 Sediment Pond S1
Channel
#5
==>
#6
0.000
0.000 Diversion Channel D3
Channel
#6
==>
End
0.000
0.000 Diversion Channel D1
#5
Chan'l
#2
Chan'l
#1
Chan'l
#4
Pond
#6
Chan'l
Printed 03-22-2011
4
Structure Summary:
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
#5
115.900
Peak
Discharge
(cfs)
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
115.900
436.30
82.76
2,340.1
35,730
0.61
0.35
#2
75.850
75.850
465.53
56.63
4,097.5
98,301
18.65
9.81
#1
122.820
122.820
530.72
91.52
5,151.2
72,373
4.39
2.46
0.000
198.670
887.40
148.14
9,248.7
81,934
9.65
5.29
804.17
148.14
8,330.6
62,673
2.80
1.95
134.000
448.570
1,827.19
325.32
12,958.1
44,801
2.15
1.53
#4
In
Out
#6
Printed 03-22-2011
5
Particle Size Distribution(s) at Each Structure
Structure #5 (Diversion Channel D3):
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
100.000%
0.0740
100.000%
0.0458
100.000%
0.0330
100.000%
0.0212
100.000%
0.0153
100.000%
0.0093
96.703%
0.0044
88.409%
0.0023
79.618%
0.0010
73.813%
Structure #2 (Collection Channel C5):
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
96.467%
0.0740
90.239%
0.0458
88.968%
0.0330
86.172%
0.0212
82.740%
0.0153
79.690%
0.0093
74.098%
0.0044
67.743%
Printed 03-22-2011
6
Size (mm)
In/Out
0.0023
61.007%
0.0010
56.558%
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
100.000%
0.0740
100.000%
0.0458
100.000%
0.0330
100.000%
0.0212
100.000%
0.0153
97.012%
0.0093
90.204%
0.0044
82.468%
0.0023
74.267%
0.0010
68.852%
Structure #4 (Sediment Pond S1):
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
100.000%
100.000%
0.1490
98.435%
100.000%
0.0740
95.675%
100.000%
0.0458
95.112%
100.000%
0.0330
93.874%
100.000%
0.0212
92.353%
100.000%
0.0153
89.337%
99.183%
0.0093
83.068%
92.223%
0.0044
75.944%
84.314%
0.0023
68.392%
75.930%
0.0010
63.405%
70.393%
Printed 03-22-2011
7
Structure #6:
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
100.000%
0.0740
100.000%
0.0458
100.000%
0.0330
100.000%
0.0212
99.268%
0.0153
98.119%
0.0093
91.905%
0.0044
84.023%
0.0023
75.668%
0.0010
70.151%
Printed 03-22-2011
8
Structure Detail:
Structure #5 (Riprap Channel)
Diversion Channel D3
Trapezoidal Riprap Channel Inputs:
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
4.7
Freeboard
Mult. x
(VxD)
1.00
Riprap Channel Results:
PADER Method - Steep Slope Design
w/o Freeboard
w/ Freeboard
Design Discharge:
436.30 cfs
Depth:
2.48 ft
3.48 ft
Top Width:
22.07 ft
26.07 ft
Velocity:
10.27 fps
X-Section Area:
42.47 sq ft
Hydraulic Radius:
1.827 ft
Froude Number:
1.30
Manning's n:
0.0470
Dmin:
5.00 in
D50:
9.00 in
Dmax:
12.00 in
Collection Channel C5
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
2.0:1
Right
Sideslope
Ratio
2.0:1
Slope (%)
5.0
Freeboard
Freeboard
Depth (ft)
% of Depth
Freeboard
Mult. x
(VxD)
1.00
Printed 03-22-2011
9
w/o Freeboard
w/ Freeboard
Design Discharge:
465.53 cfs
Depth:
2.53 ft
3.53 ft
Top Width:
22.26 ft
26.26 ft
Velocity:
10.70 fps
X-Section Area:
43.50 sq ft
Hydraulic Radius:
1.855 ft
Froude Number:
1.35
Manning's n:
0.0470
Dmin:
5.00 in
D50:
9.00 in
Dmax:
12.00 in
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
3.3
Freeboard
Mult. x
(VxD)
1.00
w/o Freeboard
w/ Freeboard
Design Discharge:
530.72 cfs
Depth:
2.97 ft
3.97 ft
Top Width:
24.01 ft
28.01 ft
Velocity:
9.90 fps
X-Section Area:
53.63 sq ft
Hydraulic Radius:
2.111 ft
Froude Number:
1.17
Manning's n:
0.0450
Dmin:
5.00 in
D50:
9.00 in
Dmax:
12.00 in
Structure #4 (Pond)
Sediment Pond S1
Pond Inputs:
Printed 03-22-2011
10
Initial Pool Elev:
2,225.00 ft
Initial Pool:
0.00 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
0.00 %
*No sediment capacity defined
Perforated Riser
Riser
Diameter
(in)
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
29.00
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
4.00
0.0240
2,253.50
350.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
50.00
2,253.70
Pond Results:
Peak Elevation:
2,256.55 ft
H'graph Detention Time:
3.32 hrs
Pond Model:
CSTRS
Dewater Time:
1.25 days
Trap Efficiency:
9.93 %
Dewatering time is calculated from peak stage to lowest spillway
Elevation-Capacity-Discharge Table
Elevation
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,224.50
0.000
0.000
0.000
Top of Sed. Storage
2,225.00
0.003
0.000
0.000
Low hole SPW #1
2,225.50
0.010
0.003
0.297
0.50
2,226.00
0.022
0.011
0.420
0.25
2,226.50
0.039
0.026
0.812
0.30
2,227.00
0.060
0.051
1.014
0.35
2,227.50
0.087
0.088
1.476
0.35
2,228.00
0.119
0.139
1.742
0.40
2,228.50
0.155
0.207
2.262
0.40
2,229.00
0.195
0.294
2.583
0.45
2,229.50
0.241
0.403
3.154
0.45
2,230.00
0.292
0.536
3.522
0.45
2,230.50
0.348
0.696
4.139
0.55
2,231.00
0.408
0.884
4.551
0.50
Printed 03-22-2011
Elevation
11
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,231.10
0.420
0.926
4.760
0.10
2,231.50
0.429
1.096
5.210
0.40
2,232.00
0.441
1.313
5.663
0.50
2,232.50
0.452
1.536
6.361
0.45
2,233.00
0.464
1.765
6.852
0.45
2,233.50
0.476
2.000
7.586
0.35
2,234.00
0.488
2.241
8.112
0.40
2,234.50
0.500
2.489
8.881
0.35
2,235.00
0.513
2.742
9.441
0.35
2,235.50
0.525
3.002
10.243
0.30
2,236.00
0.538
3.268
10.834
0.30
2,236.50
0.551
3.540
11.668
0.30
2,237.00
0.564
3.819
12.290
0.30
2,237.50
0.577
4.104
13.153
0.25
2,237.60
0.580
4.162
13.290
0.05
2,238.00
0.613
4.400
13.805
0.20
2,238.50
0.655
4.717
14.697
0.30
2,239.00
0.699
5.056
15.377
0.25
2,239.50
0.745
5.417
16.297
0.30
2,240.00
0.791
5.801
17.005
0.25
2,240.50
0.840
6.209
17.951
0.30
2,241.00
0.889
6.641
18.685
0.30
2,241.50
0.940
7.098
19.658
0.25
2,242.00
0.993
7.581
20.418
0.30
2,242.50
1.046
8.091
21.416
0.30
2,243.00
1.102
8.628
22.200
0.30
2,243.50
1.158
9.193
23.223
0.30
2,244.00
1.216
9.787
24.032
0.30
2,244.20
1.240
10.032
24.525
0.15
2,244.50
1.276
10.409
25.079
0.15
2,245.00
1.336
11.062
25.911
0.35
2,245.50
1.398
11.746
26.981
0.30
2,246.00
1.461
12.461
27.837
0.30
2,246.50
1.526
13.207
28.929
0.30
2,247.00
1.592
13.987
29.808
0.35
2,247.50
1.659
14.800
30.923
0.30
2,248.00
1.728
15.647
31.823
0.35
2,248.50
1.799
16.528
32.959
0.35
2,249.00
1.870
17.446
33.881
0.35
2,249.50
1.943
18.399
35.039
0.35
2,250.00
2.018
19.389
35.982
0.35
2,250.50
2.094
20.417
37.161
0.45
2,250.80
2.140
21.052
37.748
0.45
Printed 03-22-2011
Elevation
12
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,251.00
2.180
21.484
38.125
0.35
2,251.50
2.282
22.600
39.324
0.90
2,252.00
2.386
23.767
40.308
0.90
2,252.50
2.492
24.986
41.528
0.85
2,253.00
2.601
26.259
42.531
1.00
2,253.50
2.712
27.587
43.771
1.35
Spillway #1
2,253.70
2.757
28.134
44.190
0.95
Spillway #2
2,254.00
2.825
28.971
70.163
2.20
2,254.50
2.941
30.413
156.210
1.55
2,255.00
3.058
31.912
275.470
0.75
2,255.50
3.178
33.471
420.896
0.30
2,256.00
3.301
35.091
592.223
0.25
2,256.50
3.426
36.773
782.145
0.30
2,256.55
3.440
36.958
804.171
0.05 Peak Stage
2,257.00
3.553
38.517
988.984
2,257.30
3.630
39.595
1,120.681
Detailed Discharge Table
Combined
Elevation
(ft)
BroadPerf. Riser (cfs)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,224.50
0.000
0.000
0.000
2,225.00
2.00>0.000
0.000
0.000
2,225.50
0.297
0.000
0.297
2,226.00
2.00>0.420
0.000
0.420
2,226.50
0.812
0.000
0.812
2,227.00
2.00>1.014
0.000
1.014
2,227.50
1.476
0.000
1.476
2,228.00
2.00>1.742
0.000
1.742
2,228.50
2.262
0.000
2.262
2,229.00
2.00>2.583
0.000
2.583
2,229.50
3.154
0.000
3.154
2,230.00
2.00>3.522
0.000
3.522
2,230.50
4.139
0.000
4.139
2,231.00
2.00>4.551
0.000
4.551
2,231.10
4.760
0.000
4.760
2,231.50
5.210
0.000
5.210
2,232.00
2.00>5.663
0.000
5.663
2,232.50
6.361
0.000
6.361
2,233.00
2.00>6.852
0.000
6.852
2,233.50
7.586
0.000
7.586
Printed 03-22-2011
13
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,234.00
2.00>8.112
0.000
8.112
2,234.50
8.881
0.000
8.881
2,235.00
2.00>9.441
0.000
9.441
2,235.50
10.243
0.000
10.243
2,236.00
2.00>10.834
0.000
10.834
2,236.50
11.668
0.000
11.668
2,237.00
2.00>12.290
0.000
12.290
2,237.50
13.153
0.000
13.153
2,237.60
13.290
0.000
13.290
2,238.00
2.00>13.805
0.000
13.805
2,238.50
14.697
0.000
14.697
2,239.00
2.00>15.377
0.000
15.377
2,239.50
16.297
0.000
16.297
2,240.00
2.00>17.005
0.000
17.005
2,240.50
17.951
0.000
17.951
2,241.00
2.00>18.685
0.000
18.685
2,241.50
19.658
0.000
19.658
2,242.00
2.00>20.418
0.000
20.418
2,242.50
21.416
0.000
21.416
2,243.00
2.00>22.200
0.000
22.200
2,243.50
23.223
0.000
23.223
2,244.00
2.00>24.032
0.000
24.032
2,244.20
24.525
0.000
24.525
2,244.50
25.079
0.000
25.079
2,245.00
2.00>25.911
0.000
25.911
2,245.50
26.981
0.000
26.981
2,246.00
2.00>27.837
0.000
27.837
2,246.50
28.929
0.000
28.929
2,247.00
2.00>29.808
0.000
29.808
2,247.50
30.923
0.000
30.923
2,248.00
2.00>31.823
0.000
31.823
2,248.50
32.959
0.000
32.959
2,249.00
2.00>33.881
0.000
33.881
2,249.50
35.039
0.000
35.039
2,250.00
2.00>35.982
0.000
35.982
2,250.50
37.161
0.000
37.161
2,250.80
37.748
0.000
37.748
2,251.00
2.00>38.125
0.000
38.125
2,251.50
39.324
0.000
39.324
2,252.00
2.00>40.308
0.000
40.308
2,252.50
41.528
0.000
41.528
Printed 03-22-2011
14
Combined
Broad-
Elevation
(ft)
Perf. Riser (cfs)
Total
crested Weir
(cfs)
Discharge
(cfs)
2,253.00
2.00>42.531
0.000
42.531
2,253.50
43.771
0.000
43.771
2,253.70
44.190
0.000
44.190
2,254.00
44.794
25.368
70.163
2,254.50
45.756
110.454
156.210
2,255.00
46.675
228.795
275.470
2,255.50
48.133
372.763
420.896
2,256.00
53.814
538.409
592.223
2,256.50
58.950
723.194
782.145
2,257.00
63.674
925.310
988.984
2,257.30
66.347
1,054.334
1,120.681
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
15.00
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
4.4
Freeboard
Mult. x
(VxD)
1.00
w/o Freeboard
w/ Freeboard
Design Discharge:
1,827.19 cfs
Depth:
5.06 ft
6.06 ft
Top Width:
35.25 ft
39.25 ft
Velocity:
14.36 fps
X-Section Area:
127.21 sq ft
Hydraulic Radius:
3.379 ft
Froude Number:
1.33
Manning's n:
0.0490
Dmin:
12.00 in
D50:
15.00 in
Dmax:
24.00 in
Printed 03-22-2011
15
Subwatershed Hydrology Detail:
Stru
#
SWS
#
#5
1
Σ
#2
Σ
#4
(ac)
Musk K
(hrs)
(hrs)
115.900
0.960
Curve
Musk X
0.000
UHS
Number
0.000
86.200
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
115.900
1
#1
Time of
Conc
SWS Area
75.850
0.364
0.000
0.000
89.700
M
75.850
1
122.820
0.793
0.000
0.000
89.800
M
436.30
82.762
436.30
82.762
465.53
56.627
465.53
56.627
530.72
91.516
Σ
122.820
530.72
91.516
Σ
198.670
887.40
148.143
620.60
94.418
1,827.19
325.323
#6
1
Σ
134.000
0.657
0.000
0.000
85.000
M
448.570
Subwatershed Sedimentology Detail:
Stru
#
SWS
#
#5
1
Soil K
0.145
L (ft)
425.00
S (%)
7.70
C
0.2180
P
1.0000
PS #
1
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc
(mg/l)
(ml/l)
24VW
(ml/l)
2,340.1
35,730
0.61
0.35
2,340.1
35,730
0.61
0.35
4,097.5
98,301
18.65
9.81
4,097.5
98,301
18.65
9.81
5,151.2
72,373
4.39
2.46
Σ
5,151.2
72,373
4.39
2.46
Σ
9,248.7
81,934
9.65
5.29
2,287.4
31,954
3.05
1.69
12,958.1
44,801
2.15
1.53
Σ
#2
1
0.145
800.00
4.00
0.7870
1.0000
1
Σ
#1
#4
Sediment
1
#6
1
0.145
0.145
Σ
600.00
200.00
4.00
8.25
0.7870
0.2180
1.0000
1.0000
1
1
Printed 03-22-2011
1
Nkamouna ESCP
Culverts V1 and V2
J. Kunkel
Knight Piesold
Filename: V1-V2.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Filename: V1-V2.sc4
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Printed 03-22-2011
3
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Musk. X
Description
Culvert
#1
==>
#2
0.000
0.000 Culvert V1
Culvert
#2
==>
End
0.000
0.000 Culvert V2
#1
Culvert
#2
Culvert
Filename: V1-V2.sc4
Printed 03-22-2011
4
Structure Summary:
Filename: V1-V2.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
Peak
Discharge
(cfs)
Total
Runoff
Volume
(ac-ft)
#1
84.250
84.250
352.05
59.29
#2
100.560
184.810
730.74
130.07
Printed 03-22-2011
5
Structure Detail:
Structure #1 (Culvert)
Culvert V1
Culvert Inputs:
Length (ft)
140.00
Slope (%)
3.62
Manning's n
0.0240
Max.
Headwater
(ft)
Tailwater
(ft)
6.60
Entrance
Loss Coef.
(Ke)
1.50
0.90
Culvert Results:
Design Discharge = 352.05 cfs
Minimum pipe diameter: 1 - 120 inch pipe(s) required
Culvert V2
Culvert Inputs:
Length (ft)
150.00
Slope (%)
3.50
Manning's n
0.0240
Max.
Headwater
(ft)
Tailwater
(ft)
7.00
Entrance
Loss Coef.
(Ke)
1.50
0.90
Culvert Results:
Filename: V1-V2.sc4
Printed 03-22-2011
6
Stru
#
SWS
#
#1
1
Σ
#2
SWS Area
(ac)
84.250
Time of
Conc
(hrs)
0.790
Musk K
(hrs)
0.000
Musk X
0.000
Curve
Number
85.000
UHS
M
84.250
1
Σ
Filename: V1-V2.sc4
100.560
184.810
0.920
0.000
0.000
85.000
M
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
352.05
59.286
352.05
59.286
384.42
70.784
730.74
130.070
Printed 03-22-2011
1
Nkamouna ESCP
Culverts V3and V4
J. Kunkel
Knight Piesold
Filename: V3-V4.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Filename: V3-V4.sc4
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Printed 03-22-2011
3
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Musk. X
Description
Culvert
#1
==>
#2
0.000
0.000 Culvert V3
Culvert
#2
==>
End
0.000
0.000 Culvert V4
#1
Culvert
#2
Culvert
Filename: V3-V4.sc4
Printed 03-22-2011
4
Structure Summary:
Filename: V3-V4.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
Peak
Discharge
(cfs)
Total
Runoff
Volume
(ac-ft)
#1
40.030
40.030
240.85
29.58
#2
51.640
91.670
501.25
67.83
Printed 03-22-2011
5
Structure Detail:
Culvert V3
Culvert Inputs:
Length (ft)
140.00
Slope (%)
3.86
Manning's n
0.0240
Max.
Headwater
(ft)
Tailwater
(ft)
6.60
Entrance
Loss Coef.
(Ke)
1.50
0.90
Culvert Results:
Culvert V4
Culvert Inputs:
Length (ft)
150.00
Slope (%)
3.86
Manning's n
0.0240
Max.
Headwater
(ft)
Tailwater
(ft)
7.00
Entrance
Loss Coef.
(Ke)
1.50
0.90
Culvert Results:
Filename: V3-V4.sc4
Printed 03-22-2011
6
Stru
#
SWS
#
#1
1
Σ
#2
SWS Area
(ac)
40.030
Time of
Conc
(hrs)
0.385
Musk K
(hrs)
0.000
Musk X
0.000
Curve
Number
89.000
UHS
M
40.030
1
Σ
Filename: V3-V4.sc4
51.640
91.670
0.547
0.000
0.000
89.200
M
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
240.85
29.584
240.85
29.584
270.69
38.248
501.25
67.832
Printed 03-22-2011
1
Nkamouna ESCP
Culvert V5
J. Kunkel
Knight Piesold
Filename: V5Y25.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Filename: V5Y25.sc4
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Printed 03-22-2011
3
Type
Stru
#
Culvert
#1
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
Description
0.000 Culvert V5
#1
Culvert
Filename: V5Y25.sc4
Printed 03-22-2011
4
Structure Summary:
#1
Filename: V5Y25.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
39.530
39.530
Peak
Discharge
(cfs)
321.72
Total
Runoff
Volume
(ac-ft)
33.46
Printed 03-22-2011
5
Structure Detail:
Culvert V5
Culvert Inputs:
Length (ft)
150.00
Slope (%)
5.42
Manning's n
0.0240
Max.
Headwater
(ft)
Tailwater
(ft)
7.00
Entrance
Loss Coef.
(Ke)
1.50
0.90
Culvert Results:
Filename: V5Y25.sc4
Printed 03-22-2011
6
Stru
#
SWS
#
#1
1
Σ
Filename: V5Y25.sc4
SWS Area
(ac)
39.530
39.530
Time of
Conc
(hrs)
0.270
Musk K
(hrs)
0.000
Musk X
0.000
Curve
Number
85.800
UHS
F
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
321.72
33.455
321.72
33.455
Printed 03-22-2011
1
Nkamouna ESCP
Sediment Pond S2 (With Emerg. Splwy)
New Ore Stockpile
J. Kunkel
Knight Piesold
Filename: NewS2Y.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Musk. X
Description
Channel
#1
==>
#5
0.000
Channel
#4
==>
#5
0.000
Pond
#5
==>
End
0.000
#4
Chan'l
#1
Chan'l
#5
Pond
Printed 03-22-2011
4
Structure Summary:
#4
#1
#5
In
Out
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
25.140
25.140
34.420
34.420
0.000
59.560
Peak
Discharge
(cfs)
174.37
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
18.94
501.8
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
36,904
8.45
24VW
(ml/l)
4.41
171.37
25.73
592.5
31,034
3.58
1.94
323.33
44.67
1,094.3
33,082
5.54
2.99
108.83
44.67
862.0
22,311
0.28
0.19
Printed 03-22-2011
5
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
95.711%
0.1490
90.130%
0.0740
84.311%
0.0458
83.124%
0.0330
80.511%
0.0212
77.305%
0.0153
74.455%
0.0093
69.230%
0.0044
63.293%
0.0023
56.999%
0.0010
52.843%
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
100.000%
0.0740
100.000%
0.0458
100.000%
0.0330
96.936%
0.0212
93.075%
0.0153
89.644%
0.0093
83.353%
0.0044
76.205%
Printed 03-22-2011
6
Size (mm)
In/Out
0.0023
68.627%
0.0010
63.623%
Structure #5:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
98.033%
100.000%
0.1490
95.474%
100.000%
0.0740
92.806%
100.000%
0.0458
92.262%
100.000%
0.0330
89.405%
100.000%
0.0212
85.844%
100.000%
0.0153
82.679%
100.000%
0.0093
76.877%
97.595%
0.0044
70.284%
89.225%
0.0023
63.295%
80.353%
0.0010
58.680%
74.494%
Printed 03-22-2011
7
Structure Detail:
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
9.4
Freeboard
Mult. x
(VxD)
1.00
w/o Freeboard
w/ Freeboard
Design Discharge:
174.37 cfs
Depth:
1.31 ft
2.31 ft
Top Width:
17.38 ft
21.38 ft
Velocity:
9.02 fps
X-Section Area:
19.33 sq ft
Hydraulic Radius:
1.074 ft
Froude Number:
1.51
Manning's n:
0.0530
Dmin:
5.00 in
D50:
9.00 in
Dmax:
12.00 in
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
2.0:1
Right
Sideslope
Ratio
2.0:1
Slope (%)
3.9
Freeboard
Freeboard
Depth (ft)
% of Depth
Freeboard
Mult. x
(VxD)
1.00
Printed 03-22-2011
8
w/o Freeboard
w/ Freeboard
Design Discharge:
171.37 cfs
Depth:
1.52 ft
2.52 ft
Top Width:
18.22 ft
22.22 ft
Velocity:
7.43 fps
X-Section Area:
23.07 sq ft
Hydraulic Radius:
1.218 ft
Froude Number:
1.16
Manning's n:
0.0450
Dmin:
3.00 in
D50:
6.00 in
Dmax:
9.00 in
Structure #5 (Pond)
Sediment Pond S2
Pond Inputs:
Initial Pool Elev:
2,100.84 ft
Initial Pool:
0.00 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Riser
Diameter
(in)
36.00
Riser Height
(ft)
10.00
Barrel
Diameter
(in)
36.00
Barrel
Length (ft)
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
4.50
0.0240
2,109.84
213.00
Number of
Holes per
Elev
4
Pond Results:
Peak Elevation:
2,120.07 ft
1.99 hrs
Pond Model:
CSTRS
Dewater Time:
0.92 days
Trap Efficiency:
21.23 %
Printed 03-22-2011
Elevation
9
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,099.84
0.000
0.000
0.000
2,100.34
0.003
0.000
0.000
Top of Sed. Storage
2,100.84
0.010
0.003
0.000
2,101.34
0.022
0.011
0.297
1.30
2,101.84
0.039
0.027
0.420
0.55
2,102.34
0.061
0.051
0.812
0.50
2,102.84
0.088
0.089
1.014
0.50
2,103.34
0.120
0.140
1.476
0.50
2,103.84
0.156
0.209
1.742
0.50
2,104.34
0.198
0.298
2.262
0.55
2,104.84
0.244
0.408
2.583
0.55
2,105.34
0.296
0.543
3.154
0.60
2,105.84
0.352
0.704
3.522
0.55
2,106.34
0.413
0.895
4.139
0.60
2,106.40
0.420
0.920
4.192
0.10
2,106.84
0.454
1.113
4.551
0.55
2,107.34
0.495
1.350
5.210
0.55
2,107.84
0.537
1.608
5.663
0.60
2,108.34
0.581
1.887
6.361
0.55
2,108.84
0.627
2.189
6.852
0.60
2,109.34
0.674
2.515
7.586
0.60
2,109.84
0.724
2.864
8.112
2.40
2,110.34
0.775
3.239
10.330
3.65
2,110.84
0.827
3.639
29.217
2.55
2,111.34
0.882
4.066
41.684
0.25
2,111.84
0.938
4.521
48.133
0.20
2,112.34
0.996
5.005
53.814
0.20
2,112.84
1.056
5.517
58.950
0.15
2,112.96
1.070
5.645
60.117
0.05
2,113.34
1.106
6.058
63.674
0.10
2,113.84
1.153
6.623
68.070
0.15
2,114.34
1.202
7.212
72.199
0.15
2,114.84
1.252
7.825
76.105
0.15
2,115.34
1.302
8.463
79.819
0.15
2,115.84
1.354
9.127
83.369
0.10
2,116.34
1.406
9.817
86.773
0.15
2,116.84
1.460
10.534
90.048
0.15
2,117.34
1.515
11.278
93.209
0.15
2,117.84
1.570
12.049
96.266
0.20
2,118.34
1.627
12.848
99.228
0.15
2,118.84
1.685
13.676
102.105
0.20
2,119.34
1.744
14.533
104.903
0.20
2,119.53
1.766
14.867
105.947
0.10
Low hole SPW #1
Spillway #1
Printed 03-22-2011
Elevation
10
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,119.84
1.786
15.417
107.628
0.20
2,120.07
1.801
15.826
108.835
0.20 Peak Stage
2,120.34
1.819
16.319
110.286
2,120.84
1.853
17.237
112.676
2,121.34
1.886
18.171
113.593
2,121.84
1.920
19.123
114.503
2,122.34
1.954
20.092
115.406
2,122.84
1.989
21.077
116.302
2,123.34
2.024
22.081
117.191
2,123.84
2.059
23.101
118.073
2,124.34
2.094
24.140
118.949
2,124.84
2.130
25.196
119.818
2,125.34
2.166
26.270
120.681
2,125.84
2.202
27.362
121.538
2,126.08
2.220
27.893
121.947
Combined
Elevation
(ft)
Perf. Riser (cfs)
Total
Discharge
(cfs)
2,099.84
0.000
0.000
2,100.34
0.000
0.000
2,100.84
2.00>0.000
0.000
2,101.34
0.297
0.297
2,101.84
2.00>0.420
0.420
2,102.34
0.812
0.812
2,102.84
2.00>1.014
1.014
2,103.34
1.476
1.476
2,103.84
2.00>1.742
1.742
2,104.34
2.262
2.262
2,104.84
2.00>2.583
2.583
2,105.34
3.154
3.154
2,105.84
2.00>3.522
3.522
2,106.34
4.139
4.139
2,106.40
4.192
4.192
2,106.84
2.00>4.551
4.551
2,107.34
5.210
5.210
2,107.84
2.00>5.663
5.663
2,108.34
6.361
6.361
2,108.84
2.00>6.852
6.852
2,109.34
7.586
7.586
Printed 03-22-2011
11
Combined
Elevation
(ft)
Perf. Riser (cfs)
Total
Discharge
(cfs)
2,109.84
8.112
8.112
2,110.34
10.330
10.330
2,110.84
29.217
29.217
2,111.34
41.684
41.684
2,111.84
48.133
48.133
2,112.34
53.814
53.814
2,112.84
58.950
58.950
2,112.96
60.117
60.117
2,113.34
63.674
63.674
2,113.84
68.070
68.070
2,114.34
72.199
72.199
2,114.84
76.105
76.105
2,115.34
79.819
79.819
2,115.84
83.369
83.369
2,116.34
86.773
86.773
2,116.84
90.048
90.048
2,117.34
93.209
93.209
2,117.84
96.266
96.266
2,118.34
99.228
99.228
2,118.84
102.105
102.105
2,119.34
104.903
104.903
2,119.53
105.947
105.947
2,119.84
107.628
107.628
2,120.34
110.286
110.286
2,120.84
112.676
112.676
2,121.34
113.593
113.593
2,121.84
114.503
114.503
2,122.34
115.406
115.406
2,122.84
116.302
116.302
2,123.34
117.191
117.191
2,123.84
118.073
118.073
2,124.34
118.949
118.949
2,124.84
119.818
119.818
2,125.34
120.681
120.681
2,125.84
121.538
121.538
2,126.08
121.947
121.947
Printed 03-22-2011
12
Stru
#
SWS
#
#4
1
Σ
#1
#5
Time of
Conc
SWS Area
(ac)
Musk K
(hrs)
(hrs)
25.140
0.193
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
25.140
1
34.420
0.613
0.000
0.000
90.000
M
174.37
18.943
174.37
18.943
171.37
25.729
Σ
34.420
171.37
25.729
Σ
59.560
323.33
44.672
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
Stru
#
SWS
#
#4
1
Soil K
0.145
L (ft)
650.00
S (%)
2.00
C
0.7870
P
1.0000
PS #
1
(tons)
(ml/l)
501.8
36,904
8.45
4.41
501.8
36,904
8.45
4.41
592.5
31,034
3.58
1.94
Σ
592.5
31,034
3.58
1.94
Σ
1,094.3
33,082
5.54
2.99
Σ
#1
#5
Sediment
1
0.145
650.00
2.00
0.7870
1.0000
1
Printed 03-22-2011
1
Nkamouna ESCP
Sediment Pond S3 (With Emerg. Splwy) New Ore Stockpile
J. Kunkel
Knight Piesold
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
Pond
#6
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
Description
#6
Pond
Printed 03-22-2011
4
Structure Summary:
#6
In
Out
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
49.110
49.110
Peak
Discharge
(cfs)
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
328.15
37.07
1,040.3
38,923
8.45
4.43
293.49
37.07
811.0
29,728
1.69
0.91
Printed 03-22-2011
5
Structure #6:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
97.732%
100.000%
0.1490
92.033%
100.000%
0.0740
86.092%
100.000%
0.0458
84.879%
100.000%
0.0330
82.212%
100.000%
0.0212
78.938%
100.000%
0.0153
76.028%
97.521%
0.0093
70.692%
90.678%
0.0044
64.629%
82.901%
0.0023
58.203%
74.658%
0.0010
53.959%
69.214%
Printed 03-22-2011
6
Structure Detail:
Structure #6 (Pond)
Sediment Pond S3
Pond Inputs:
Initial Pool Elev:
2,100.84 ft
Initial Pool:
0.00 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Riser
Diameter
(in)
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
10.00
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
7.00
0.0240
2,109.84
245.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
15.00
2,116.53
Pond Results:
Peak Elevation:
2,119.09 ft
0.49 hrs
Pond Model:
CSTRS
Dewater Time:
0.61 days
Trap Efficiency:
22.04 %
Elevation
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,099.84
0.000
0.000
0.000
2,100.34
0.001
0.000
0.000
Top of Sed. Storage
2,100.84
0.003
0.001
0.000
2,101.34
0.006
0.003
0.297
0.35
2,101.84
0.011
0.008
0.420
0.15
2,102.34
0.017
0.015
0.812
0.15
2,102.84
0.025
0.025
1.014
0.15
Low hole SPW #1
Printed 03-22-2011
Elevation
7
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,103.34
0.034
0.040
1.476
0.15
2,103.84
0.045
0.060
1.742
0.15
2,104.34
0.056
0.085
2.262
0.15
2,104.84
0.070
0.117
2.583
0.15
2,105.34
0.084
0.155
3.154
0.15
2,105.84
0.100
0.201
3.522
0.20
2,106.34
0.118
0.256
4.139
0.15
2,106.40
0.120
0.263
4.192
0.05
2,106.84
0.127
0.317
4.830
0.15
2,107.34
0.135
0.383
5.321
0.20
2,107.84
0.143
0.452
6.044
0.20
2,108.34
0.151
0.525
6.555
2.45
2,108.84
0.160
0.603
7.305
1.00
2,109.34
0.169
0.685
7.845
0.80
2,109.84
0.178
0.772
8.625
1.10
2,110.34
0.187
0.863
10.330
1.50
2,110.84
0.197
0.959
29.217
3.60
2,111.34
0.207
1.060
41.684
0.15
2,111.84
0.217
1.166
48.133
0.10
2,112.34
0.227
1.277
53.814
0.05
2,112.84
0.237
1.393
58.950
0.05
2,112.96
0.240
1.421
60.117
2,113.34
0.280
1.520
63.674
0.05
2,113.84
0.338
1.674
68.070
0.05
2,114.34
0.401
1.859
72.199
0.05
2,114.84
0.469
2.076
76.105
0.10
2,115.34
0.543
2.329
79.819
0.05
2,115.84
0.622
2.620
83.369
0.10
2,116.34
0.707
2.952
86.773
0.10
2,116.53
0.740
3.089
88.031
0.05
2,116.84
0.786
3.326
98.043
0.10
2,117.34
0.862
3.738
126.969
0.15
2,117.84
0.943
4.189
165.698
0.15
2,118.34
1.026
4.681
211.991
0.10
2,118.84
1.114
5.216
264.683
0.10
2,119.09
1.159
5.502
293.491
0.10 Peak Stage
2,119.34
1.205
5.795
323.026
2,119.53
1.240
6.027
346.554
Spillway #1
Spillway #2
Printed 03-22-2011
8
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,099.84
0.000
0.000
0.000
2,100.34
0.000
0.000
0.000
2,100.84
2.00>0.000
0.000
0.000
2,101.34
0.297
0.000
0.297
2,101.84
2.00>0.420
0.000
0.420
2,102.34
0.812
0.000
0.812
2,102.84
2.00>1.014
0.000
1.014
2,103.34
1.476
0.000
1.476
2,103.84
2.00>1.742
0.000
1.742
2,104.34
2.262
0.000
2.262
2,104.84
2.00>2.583
0.000
2.583
2,105.34
3.154
0.000
3.154
2,105.84
2.00>3.522
0.000
3.522
2,106.34
4.139
0.000
4.139
2,106.40
2.00>4.192
0.000
4.192
2,106.84
4.830
0.000
4.830
2,107.34
2.00>5.321
0.000
5.321
2,107.84
6.044
0.000
6.044
2,108.34
2.00>6.555
0.000
6.555
2,108.84
7.305
0.000
7.305
2,109.34
2.00>7.845
0.000
7.845
2,109.84
8.625
0.000
8.625
2,110.34
10.330
0.000
10.330
2,110.84
29.217
0.000
29.217
2,111.34
41.684
0.000
41.684
2,111.84
48.133
0.000
48.133
2,112.34
53.814
0.000
53.814
2,112.84
58.950
0.000
58.950
2,112.96
60.117
0.000
60.117
2,113.34
63.674
0.000
63.674
2,113.84
68.070
0.000
68.070
2,114.34
72.199
0.000
72.199
2,114.84
76.105
0.000
76.105
2,115.34
79.819
0.000
79.819
2,115.84
83.369
0.000
83.369
2,116.34
86.773
0.000
86.773
2,116.53
88.031
0.000
88.031
2,116.84
90.048
7.995
98.043
2,117.34
93.209
33.760
126.969
2,117.84
96.266
69.433
165.698
2,118.34
99.228
112.763
211.991
Printed 03-22-2011
9
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,118.84
102.105
162.578
264.683
2,119.34
104.903
218.123
323.026
2,119.53
105.947
240.608
346.554
Printed 03-22-2011
10
Stru
#
SWS
#
#6
1
Σ
Time of
Conc
SWS Area
(ac)
Musk K
(hrs)
(hrs)
49.110
0.235
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
328.15
37.074
328.15
37.074
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
49.110
Stru
#
SWS
#
#6
1
Σ
Soil K
0.145
L (ft)
650.00
S (%)
2.00
C
0.7870
P
1.0000
PS #
1
Sediment
(tons)
(ml/l)
1,040.3
38,923
8.45
4.43
1,040.3
38,923
8.45
4.43
Printed 03-22-2011
1
Nkamouna ESCP
New Ore Stockpile
J. Kunkel
Knight Piesold
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
Pond
#4
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
Description
#4
Pond
Printed 03-22-2011
4
Structure Summary:
#4
In
Out
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
65.680
65.680
Peak
Discharge
(cfs)
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
336.92
49.14
1,242.5
34,234
4.33
2.33
237.38
49.14
1,100.5
27,142
1.14
0.70
Printed 03-22-2011
5
Structure #4:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
100.000%
100.000%
0.1490
100.000%
100.000%
0.0740
99.828%
100.000%
0.0458
98.422%
100.000%
0.0330
95.329%
100.000%
0.0212
91.532%
100.000%
0.0153
88.158%
99.526%
0.0093
81.971%
92.542%
0.0044
74.941%
84.605%
0.0023
67.489%
76.192%
0.0010
62.568%
70.637%
Printed 03-22-2011
6
Structure Detail:
Structure #4 (Pond)
Sediment Pond S4
Pond Inputs:
Initial Pool Elev:
1,985.16 ft
Initial Pool:
2.87 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Riser
Diameter
(in)
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
10.00
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
4.00
0.0240
1,985.16
180.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
15.00
1,991.85
Pond Results:
Peak Elevation:
1,993.90 ft
0.60 hrs
Pond Model:
CSTRS
Dewater Time:
0.66 days
Trap Efficiency:
11.42 %
Elevation
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
1,975.10
0.000
0.000
0.000
1,975.60
0.003
0.000
0.000
1,976.10
0.010
0.003
0.000
1,976.60
0.022
0.011
0.000
1,977.10
0.039
0.026
0.000
1,977.60
0.060
0.051
0.000
1,978.10
0.087
0.087
0.000
Dewater
Time
(hrs)
Top of Sed. Storage
Printed 03-22-2011
Elevation
7
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
1,978.60
0.118
0.138
0.000
1,979.10
0.154
0.206
0.000
1,979.60
0.194
0.292
0.000
1,980.10
0.240
0.401
0.000
1,980.60
0.290
0.533
0.000
1,981.10
0.345
0.692
0.000
1,981.60
0.405
0.879
0.000
1,981.72
0.420
0.929
0.000
1,982.10
0.450
1.094
0.000
1,982.60
0.490
1.329
0.000
1,983.10
0.532
1.584
0.000
1,983.60
0.576
1.861
0.000
1,984.10
0.621
2.160
0.000
1,984.60
0.668
2.482
0.000
1,985.10
0.717
2.829
0.000
1,985.16
0.723
2.872
0.000
1,985.60
0.768
3.200
8.526
7.60
1,986.10
0.820
3.597
26.625
4.80
1,986.60
0.874
4.020
40.841
0.35
1,987.10
0.930
4.471
47.405
0.25
1,987.60
0.988
4.951
53.164
0.20
1,988.10
1.047
5.460
58.357
0.20
1,988.29
1.070
5.661
60.214
0.05
1,988.60
1.099
5.997
63.125
0.10
1,989.10
1.147
6.558
67.557
0.20
1,989.60
1.195
7.144
71.716
0.15
1,990.10
1.245
7.754
75.646
0.15
1,990.60
1.295
8.389
79.382
0.20
1,991.10
1.347
9.049
82.950
0.20
1,991.60
1.400
9.736
86.371
0.25
1,991.85
1.426
10.089
88.031
0.15
1,992.10
1.453
10.449
95.449
0.15
1,992.60
1.508
11.189
122.911
0.35
1,993.10
1.563
11.957
160.617
0.25
1,993.60
1.620
12.753
206.075
0.15
1,993.90
1.655
13.250
237.381
0.20 Peak Stage
1,994.10
1.678
13.577
258.043
1,994.60
1.736
14.431
315.738
1,994.85
1.766
14.869
346.554
Spillway #1
Spillway #2
Printed 03-22-2011
8
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
1,975.10
0.000
0.000
0.000
1,975.60
0.000
0.000
0.000
1,976.10
0.000
0.000
0.000
1,976.60
0.000
0.000
0.000
1,977.10
0.000
0.000
0.000
1,977.60
0.000
0.000
0.000
1,978.10
0.000
0.000
0.000
1,978.60
0.000
0.000
0.000
1,979.10
0.000
0.000
0.000
1,979.60
0.000
0.000
0.000
1,980.10
0.000
0.000
0.000
1,980.60
0.000
0.000
0.000
1,981.10
0.000
0.000
0.000
1,981.60
0.000
0.000
0.000
1,981.72
0.000
0.000
0.000
1,982.10
0.000
0.000
0.000
1,982.60
0.000
0.000
0.000
1,983.10
0.000
0.000
0.000
1,983.60
0.000
0.000
0.000
1,984.10
0.000
0.000
0.000
1,984.60
0.000
0.000
0.000
1,985.10
0.000
0.000
0.000
1,985.16
0.000
0.000
0.000
1,985.60
8.526
0.000
8.526
1,986.10
26.625
0.000
26.625
1,986.60
40.841
0.000
40.841
1,987.10
47.405
0.000
47.405
1,987.60
53.164
0.000
53.164
1,988.10
58.357
0.000
58.357
1,988.29
60.214
0.000
60.214
1,988.60
63.125
0.000
63.125
1,989.10
67.557
0.000
67.557
1,989.60
71.716
0.000
71.716
1,990.10
75.646
0.000
75.646
1,990.60
79.382
0.000
79.382
1,991.10
82.950
0.000
82.950
1,991.60
86.371
0.000
86.371
1,991.85
88.031
0.000
88.031
1,992.10
89.661
5.788
95.449
1,992.60
92.835
30.076
122.911
1,993.10
95.904
64.713
160.617
Printed 03-22-2011
9
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
1,993.60
98.877
107.198
206.075
1,994.10
101.764
156.279
258.043
1,994.60
104.571
211.167
315.738
1,994.85
105.947
240.608
346.554
Printed 03-22-2011
10
Stru
#
SWS
#
#4
1
Σ
Time of
Conc
SWS Area
(ac)
Musk K
(hrs)
(hrs)
65.680
0.578
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
336.92
49.136
336.92
49.136
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
65.680
Stru
#
SWS
#
#4
1
Σ
Soil K
0.145
L (ft)
650.00
S (%)
2.00
C
0.7870
P
1.0000
PS #
1
Sediment
(tons)
(ml/l)
1,242.5
34,234
4.33
2.33
1,242.5
34,234
4.33
2.33
Printed 03-22-2011
1
Nkamouna ESCP
New Ore Stockpile
J. Kunkel
Knight Piesold
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Musk. X
Description
Channel
#1
==>
#4
0.000
Pond
#4
==>
End
0.000
#1
Chan'l
#4
Pond
Printed 03-22-2011
4
Structure Summary:
#1
#4
In
Out
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
68.280
68.280
0.000
68.280
Peak
Discharge
(cfs)
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
398.85
51.16
1,395.6
37,793
6.53
3.43
398.85
51.16
1,395.6
37,793
6.53
3.43
104.36
51.16
1,085.8
24,640
0.27
0.18
Printed 03-22-2011
5
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
99.229%
0.0740
92.823%
0.0458
91.515%
0.0330
88.639%
0.0212
85.109%
0.0153
81.972%
0.0093
76.219%
0.0044
69.682%
0.0023
62.753%
0.0010
58.178%
Structure #4:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
100.000%
100.000%
0.1490
99.229%
100.000%
0.0740
92.823%
100.000%
0.0458
91.515%
100.000%
0.0330
88.639%
100.000%
0.0212
85.109%
100.000%
0.0153
81.972%
100.000%
0.0093
76.219%
97.968%
0.0044
69.682%
89.566%
Printed 03-22-2011
6
Size (mm)
In
Out
0.0023
62.753%
80.660%
0.0010
58.178%
74.779%
Printed 03-22-2011
7
Structure Detail:
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
2.0
Freeboard
Mult. x
(VxD)
1.00
w/o Freeboard
w/ Freeboard
Design Discharge:
398.85 cfs
Depth:
2.73 ft
3.73 ft
Top Width:
23.07 ft
27.07 ft
Velocity:
8.29 fps
X-Section Area:
48.10 sq ft
Hydraulic Radius:
1.975 ft
Froude Number:
1.01
Manning's n:
0.0400
Dmin:
3.00 in
D50:
6.00 in
Dmax:
9.00 in
Structure #4 (Pond)
Sediment Pond S5
Pond Inputs:
Initial Pool Elev:
2,100.84 ft
Initial Pool:
0.00 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Printed 03-22-2011
Riser
Diameter
(in)
8
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
10.00
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
3.50
0.0240
2,109.84
280.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
15.00
2,123.00
Pond Results:
Peak Elevation:
2,121.87 ft
2.07 hrs
Pond Model:
CSTRS
Dewater Time:
0.93 days
Trap Efficiency:
22.20 %
Elevation
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,099.84
0.000
0.000
0.000
2,100.34
0.003
0.000
0.000
Top of Sed. Storage
2,100.84
0.010
0.003
0.000
2,101.34
0.022
0.011
0.297
1.30
2,101.84
0.039
0.027
0.420
0.50
2,102.34
0.061
0.051
0.812
0.55
2,102.84
0.088
0.089
1.014
0.45
2,103.34
0.120
0.140
1.476
0.55
2,103.84
0.156
0.209
1.742
0.50
2,104.34
0.198
0.298
2.262
0.55
2,104.84
0.244
0.408
2.583
0.55
2,105.34
0.296
0.543
3.154
0.55
2,105.84
0.352
0.704
3.522
0.60
2,106.34
0.413
0.895
4.139
0.60
2,106.40
0.420
0.920
4.192
0.05
2,106.84
0.454
1.113
4.551
0.55
2,107.34
0.495
1.350
5.210
0.60
2,107.84
0.537
1.608
5.663
0.55
2,108.34
0.581
1.887
6.361
0.60
2,108.84
0.627
2.189
6.852
0.55
2,109.34
0.674
2.515
7.586
0.55
Low hole SPW #1
Printed 03-22-2011
Elevation
9
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,109.84
0.724
2.864
8.112
0.65
2,110.34
0.775
3.239
10.330
4.85
Spillway #1
2,110.84
0.827
3.639
29.217
2.80
2,111.34
0.882
4.066
41.684
0.30
2,111.84
0.938
4.521
48.133
0.20
2,112.34
0.996
5.005
53.814
0.15
2,112.84
1.056
5.517
58.950
0.15
2,112.96
1.070
5.645
60.117
0.05
2,113.34
1.106
6.058
63.674
0.10
2,113.84
1.153
6.623
68.070
0.15
2,114.34
1.202
7.212
72.199
0.15
2,114.84
1.252
7.825
76.105
0.15
2,115.34
1.302
8.463
79.819
0.15
2,115.84
1.354
9.127
83.369
0.10
2,116.34
1.406
9.817
86.773
0.15
2,116.84
1.460
10.534
90.048
0.15
2,117.34
1.515
11.278
93.209
0.10
2,117.84
1.570
12.049
96.266
0.15
2,118.34
1.627
12.848
98.406
0.15
2,118.84
1.685
13.676
99.271
0.15
2,119.34
1.744
14.533
100.130
0.15
2,119.53
1.766
14.867
100.454
0.05
2,119.84
1.786
15.417
100.980
0.10
2,120.34
1.819
16.319
101.824
0.15
2,120.84
1.853
17.237
102.661
0.20
2,121.34
1.886
18.171
103.490
0.20
2,121.84
1.920
19.123
104.314
0.45
2,121.87
1.922
19.174
104.357
0.05 Peak Stage
2,122.34
1.954
20.091
105.131
2,122.84
1.989
21.077
105.941
2,123.00
2.000
21.396
106.199
2,123.34
2.023
22.080
115.929
2,123.84
2.058
23.100
143.199
2,124.34
2.094
24.138
180.170
2,124.84
2.130
25.194
224.704
2,125.34
2.165
26.268
275.663
2,125.84
2.202
27.360
332.309
2,126.09
2.220
27.913
362.593
Spillway #2
Printed 03-22-2011
10
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,099.84
0.000
0.000
0.000
2,100.34
0.000
0.000
0.000
2,100.84
2.00>0.000
0.000
0.000
2,101.34
0.297
0.000
0.297
2,101.84
2.00>0.420
0.000
0.420
2,102.34
0.812
0.000
0.812
2,102.84
2.00>1.014
0.000
1.014
2,103.34
1.476
0.000
1.476
2,103.84
2.00>1.742
0.000
1.742
2,104.34
2.262
0.000
2.262
2,104.84
2.00>2.583
0.000
2.583
2,105.34
3.154
0.000
3.154
2,105.84
2.00>3.522
0.000
3.522
2,106.34
4.139
0.000
4.139
2,106.40
4.192
0.000
4.192
2,106.84
2.00>4.551
0.000
4.551
2,107.34
5.210
0.000
5.210
2,107.84
2.00>5.663
0.000
5.663
2,108.34
6.361
0.000
6.361
2,108.84
2.00>6.852
0.000
6.852
2,109.34
7.586
0.000
7.586
2,109.84
8.112
0.000
8.112
2,110.34
10.330
0.000
10.330
2,110.84
29.217
0.000
29.217
2,111.34
41.684
0.000
41.684
2,111.84
48.133
0.000
48.133
2,112.34
53.814
0.000
53.814
2,112.84
58.950
0.000
58.950
2,112.96
60.117
0.000
60.117
2,113.34
63.674
0.000
63.674
2,113.84
68.070
0.000
68.070
2,114.34
72.199
0.000
72.199
2,114.84
76.105
0.000
76.105
2,115.34
79.819
0.000
79.819
2,115.84
83.369
0.000
83.369
2,116.34
86.773
0.000
86.773
2,116.84
90.048
0.000
90.048
2,117.34
93.209
0.000
93.209
2,117.84
96.266
0.000
96.266
2,118.34
98.406
0.000
98.406
2,118.84
99.271
0.000
99.271
Printed 03-22-2011
11
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,119.34
100.130
0.000
100.130
2,119.53
100.454
0.000
100.454
2,119.84
100.980
0.000
100.980
2,120.34
101.824
0.000
101.824
2,120.84
102.661
0.000
102.661
2,121.34
103.490
0.000
103.490
2,121.84
104.314
0.000
104.314
2,122.34
105.131
0.000
105.131
2,122.84
105.941
0.000
105.941
2,123.00
106.199
0.000
106.199
2,123.34
106.746
9.184
115.929
2,123.84
107.544
35.655
143.199
2,124.34
108.337
71.834
180.170
2,124.84
109.123
115.581
224.704
2,125.34
109.905
165.759
275.663
2,125.84
110.680
221.628
332.309
2,126.09
111.066
251.527
362.593
Printed 03-22-2011
12
Stru
#
SWS
#
#1
#4
1
Time of
Conc
SWS Area
(ac)
Musk K
(hrs)
(hrs)
68.280
0.429
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
398.85
51.159
Σ
68.280
398.85
51.159
Σ
68.280
398.85
51.159
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
Stru
#
SWS
#
#1
#4
1
Soil K
650.00
S (%)
2.00
C
0.7870
P
1.0000
PS #
1
(tons)
(ml/l)
1,395.6
37,793
6.53
3.43
Σ
1,395.6
37,793
6.53
3.43
Σ
1,395.6
37,793
6.53
3.43
0.145
L (ft)
Sediment
Printed 03-22-2011
1
Nkamouna ESCP
Sediment Pond S6
J. Kunkel
Filename: NewS6.sc4
Printed 04-08-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Filename: NewS6.sc4
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 04-08-2011
3
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Channel
#1
==>
#2
0.000
0.000 Channel C7
Pond
#2
==>
End
0.000

Musk. X
Description
#1
Chan'l
#2
Pond
Filename: NewS6.sc4
Printed 04-08-2011
4
Structure Summary:
#1
#2
In
Out
Filename: NewS6.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
87.370
87.370
8.640
96.010
Peak
Discharge
(cfs)
Total
Runoff
Volume
(ac-ft)
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
513.87
65.50
4,185.9
86,847
15.20
8.02
529.06
73.13
4,219.5
84,507
14.89
7.30
521.23
73.13
3,666.3
71,786
6.07
3.09
Printed 04-08-2011
5
Structure #1 (Channel C7):
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
98.848%
0.0740
92.467%
0.0458
91.165%
0.0330
88.299%
0.0212
84.783%
0.0153
81.657%
0.0093
75.927%
0.0044
69.415%
0.0023
62.513%
0.0010
57.955%
Structure #2:
Size (mm)
Filename: NewS6.sc4
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
99.882%
100.000%
0.2460
99.846%
100.000%
0.1490
98.666%
100.000%
0.0740
92.296%
100.000%
0.0458
90.996%
100.000%
0.0330
88.137%
100.000%
0.0212
84.627%
97.395%
0.0153
81.507%
93.804%
Printed 04-08-2011
6
Size (mm)
Filename: NewS6.sc4
In
Out
0.0093
75.787%
87.222%
0.0044
69.287%
79.741%
0.0023
62.398%
71.812%
0.0010
57.848%
66.576%
Printed 04-08-2011
7
Structure Detail:
Channel C7
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
1.9
Freeboard
Mult. x
(VxD)
1.00
w/o Freeboard
w/ Freeboard
Design Discharge:
513.87 cfs
Depth:
3.18 ft
4.18 ft
Top Width:
24.87 ft
28.87 ft
Velocity:
8.73 fps
X-Section Area:
58.89 sq ft
Hydraulic Radius:
2.233 ft
Froude Number:
1.00
Manning's n:
0.0400
Dmin:
3.00 in
D50:
6.00 in
Dmax:
9.00 in
Structure #2 (Pond)
Sediment Pond S6
Pond Inputs:
Initial Pool Elev:
2,146.80 ft
Initial Pool:
0.00 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Filename: NewS6.sc4
Printed 04-08-2011
Riser
Diameter
(in)
8
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
15.00
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
6.00
0.0240
2,161.18
250.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
25.00
2,162.18
Pond Results:
Peak Elevation:
2,165.42 ft
0.88 hrs
Pond Model:
CSTRS
Dewater Time:
0.70 days
Trap Efficiency:
13.11 %
Elevation
Filename: NewS6.sc4
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,145.80
0.000
0.000
0.000
2,146.30
0.001
0.000
0.000
Top of Sed. Storage
2,146.80
0.002
0.001
0.000
2,147.30
0.005
0.003
0.297
0.35
2,147.80
0.009
0.006
0.420
0.10
2,148.30
0.015
0.012
0.812
0.15
2,148.80
0.021
0.021
1.014
0.10
2,149.30
0.029
0.034
1.476
0.10
2,149.80
0.038
0.051
1.742
0.15
2,150.30
0.048
0.072
2.262
0.15
2,150.80
0.059
0.099
2.583
0.10
2,151.30
0.072
0.132
3.154
0.15
2,151.80
0.085
0.171
3.522
0.15
2,152.30
0.100
0.217
4.139
0.15
2,152.80
0.120
0.272
4.551
0.15
2,153.30
0.141
0.337
5.210
0.15
2,153.80
0.164
0.413
5.663
0.15
2,154.30
0.189
0.502
6.361
0.20
2,154.80
0.216
0.603
6.852
0.20
Low hole SPW #1
Printed 04-08-2011
Elevation
9
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,155.30
0.244
0.717
7.586
0.20
2,155.80
0.274
0.847
8.112
0.20
2,156.30
0.306
0.992
8.881
0.20
2,156.80
0.340
1.153
9.441
0.20
2,157.30
0.375
1.332
10.243
0.20
2,157.80
0.412
1.529
10.834
0.25
2,158.30
0.451
1.744
11.668
0.25
2,158.80
0.492
1.980
12.290
0.25
2,158.90
0.500
2.030
12.539
0.05
2,159.30
0.521
2.234
13.153
0.25
2,159.80
0.548
2.501
13.805
0.65
2,160.30
0.575
2.782
14.697
1.35
2,160.80
0.603
3.076
15.377
1.10
2,161.18
0.625
3.310
16.113
0.75
2,161.30
0.632
3.385
16.297
0.25
2,161.80
0.662
3.708
17.005
1.80
2,162.18
0.684
3.964
29.217
3.05
2,162.30
0.692
4.047
37.849
0.95
2,162.80
0.722
4.400
81.008
1.10
2,163.30
0.754
4.769
141.047
0.50
2,163.80
0.786
5.154
214.238
0.40
2,164.30
0.819
5.555
298.360
0.10
2,164.80
0.852
5.973
392.066
0.15
2,165.30
0.886
6.408
494.421
0.10
2,165.42
0.895
6.518
521.235
0.05 Peak Stage
2,165.50
0.900
6.586
537.612
Spillway #1
Spillway #2
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
Filename: NewS6.sc4
2,145.80
0.000
0.000
0.000
2,146.30
0.000
0.000
0.000
2,146.80
2.00>0.000
0.000
0.000
2,147.30
0.297
0.000
0.297
2,147.80
2.00>0.420
0.000
0.420
2,148.30
0.812
0.000
0.812
2,148.80
2.00>1.014
0.000
1.014
2,149.30
1.476
0.000
1.476
Printed 04-08-2011
10
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,149.80
Filename: NewS6.sc4
2.00>1.742
0.000
1.742
2,150.30
2.262
0.000
2.262
2,150.80
2.00>2.583
0.000
2.583
2,151.30
3.154
0.000
3.154
2,151.80
2.00>3.522
0.000
3.522
2,152.30
4.139
0.000
4.139
2,152.80
2.00>4.551
0.000
4.551
2,153.30
5.210
0.000
5.210
2,153.80
2.00>5.663
0.000
5.663
2,154.30
6.361
0.000
6.361
2,154.80
2.00>6.852
0.000
6.852
2,155.30
7.586
0.000
7.586
2,155.80
2.00>8.112
0.000
8.112
2,156.30
8.881
0.000
8.881
2,156.80
2.00>9.441
0.000
9.441
2,157.30
10.243
0.000
10.243
2,157.80
2.00>10.834
0.000
10.834
2,158.30
11.668
0.000
11.668
2,158.80
2.00>12.290
0.000
12.290
2,158.90
12.539
0.000
12.539
2,159.30
13.153
0.000
13.153
2,159.80
2.00>13.805
0.000
13.805
2,160.30
14.697
0.000
14.697
2,160.80
2.00>15.377
0.000
15.377
2,161.18
16.113
0.000
16.113
2,161.30
16.297
0.000
16.297
2,161.80
17.005
0.000
17.005
2,162.18
29.217
0.000
29.217
2,162.30
34.636
3.213
37.849
2,162.80
43.321
37.687
81.008
2,163.30
49.557
91.490
141.047
2,163.80
55.092
159.146
214.238
2,164.30
60.119
238.241
298.360
2,164.80
64.757
327.309
392.066
2,165.30
69.085
425.337
494.421
2,165.50
70.741
466.871
537.612
Printed 04-08-2011
11
Stru
#
SWS
#
#1
(ac)
1
Musk K
(hrs)
(hrs)
87.370

#2
Time of
Conc
SWS Area
0.421
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
513.87
65.500
513.87
65.500
79.85
7.631
529.06
73.131
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
87.370
1
8.640

0.083
0.000
0.000
85.000
M
96.010
Stru
#
SWS
#
#1
Soil K
1
0.145
L (ft)
600.00
S (%)
4.00
C
0.7870
P
1.0000
PS #
1

#2
1

Filename: NewS6.sc4
0.145
200.00
2.00
0.2180
1.0000
1
Sediment
(tons)
(ml/l)
4,185.9
86,847
15.20
8.02
4,185.9
86,847
15.20
8.02
33.5
5,831
1.85
1.02
4,219.5
84,507
14.89
7.30
Printed 04-08-2011
1
Nkamouna ESCP
Sediment Pond S7
J. Kunkel
Filename: NewS7.sc4
Printed 04-08-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Filename: NewS7.sc4
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 04-08-2011
3
Type
Stru
#
Pond
#1
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
Description
#1
Pond
Filename: NewS7.sc4
Printed 04-08-2011
4
Structure Summary:
#1
In
Out
Filename: NewS7.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
133.640
133.640
Peak
Discharge
(cfs)
Total
Runoff
Volume
(ac-ft)
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
886.77
96.08
1,383.0
19,981
4.39
2.31
867.20
95.94
1,106.5
15,998
1.25
0.74
Printed 04-08-2011
5
Structure #1:
Size (mm)
Filename: NewS7.sc4
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
97.330%
100.000%
0.1490
91.655%
100.000%
0.0740
85.737%
100.000%
0.0458
84.530%
100.000%
0.0330
81.873%
100.000%
0.0212
78.613%
98.257%
0.0153
75.715%
94.635%
0.0093
70.401%
87.994%
0.0044
64.363%
80.447%
0.0023
57.963%
72.448%
0.0010
53.737%
67.165%
Printed 04-08-2011
6
Structure Detail:
Structure #1 (Pond)
Sediment Pond S7
Pond Inputs:
Initial Pool Elev:
2,244.70 ft
Initial Pool:
0.14 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Riser
Diameter
(in)
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
8.80
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
1.00
0.0240
2,253.05
200.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
50.00
2,254.05
Pond Results:
Peak Elevation:
2,257.04 ft
1.29 hrs
Pond Model:
CSTRS
Dewater Time:
1.81 days
Trap Efficiency:
19.99 %
Elevation
Filename: NewS7.sc4
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,244.20
0.260
0.000
0.000
Top of Sed. Storage
2,244.70
0.281
0.135
0.000
Low hole SPW #1
2,245.20
0.304
0.282
0.297
5.96*
2,245.70
0.327
0.439
0.420
5.35
2,246.20
0.351
0.608
0.812
3.45
2,246.70
0.375
0.790
1.014
2.40
2,247.20
0.401
0.984
1.476
1.90
Printed 04-08-2011
Elevation
7
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,247.70
0.427
1.191
1.742
1.60
2,248.20
0.455
1.411
2.262
1.30
2,248.70
0.483
1.646
2.583
1.20
2,249.20
0.512
1.894
3.154
1.05
2,249.70
0.542
2.157
3.522
0.95
2,250.20
0.572
2.436
4.139
0.90
2,250.70
0.604
2.730
4.551
0.80
2,250.80
0.610
2.791
4.760
0.15
2,251.20
0.665
3.045
5.210
0.65
2,251.70
0.737
3.396
5.663
0.75
2,252.20
0.812
3.783
6.361
0.80
2,252.70
0.891
4.208
6.852
0.75
2,253.05
0.949
4.530
7.411
0.55
2,253.20
0.974
4.674
7.586
0.25
2,253.70
1.061
5.183
15.308
0.70
Spillway #1
2,254.05
1.123
5.565
29.217
7.00
2,254.20
1.151
5.736
44.985
2.35
Spillway #2
2,254.70
1.244
6.334
124.586
1.85
2,255.20
1.342
6.981
240.230
0.30
2,255.70
1.443
7.676
382.514
0.30
2,256.20
1.547
8.424
546.963
0.10
2,256.70
1.655
9.224
730.835
0.10
2,257.04
1.732
9.804
867.204
0.10 Peak Stage
2,257.20
1.767
10.080
932.218
2,257.30
1.790
10.258
974.505
*Designates time(s) to dewater have been extrapolated beyond the 50 hour hydrograph limit.
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
Filename: NewS7.sc4
2,244.20
0.000
0.000
0.000
2,244.70
2.00>0.000
0.000
0.000
2,245.20
0.297
0.000
0.297
2,245.70
2.00>0.420
0.000
0.420
2,246.20
0.812
0.000
0.812
2,246.70
2.00>1.014
0.000
1.014
2,247.20
1.476
0.000
1.476
2,247.70
2.00>1.742
0.000
1.742
2,248.20
2.262
0.000
2.262
Printed 04-08-2011
8
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
Filename: NewS7.sc4
2,248.70
2.00>2.583
0.000
2.583
2,249.20
3.154
0.000
3.154
2,249.70
2.00>3.522
0.000
3.522
2,250.20
4.139
0.000
4.139
2,250.70
2.00>4.551
0.000
4.551
2,250.80
4.760
0.000
4.760
2,251.20
5.210
0.000
5.210
2,251.70
2.00>5.663
0.000
5.663
2,252.20
6.361
0.000
6.361
2,252.70
2.00>6.852
0.000
6.852
2,253.05
7.411
0.000
7.411
2,253.20
7.586
0.000
7.586
2,253.70
15.308
0.000
15.308
2,254.05
29.217
0.000
29.217
2,254.20
36.027
8.958
44.985
2,254.70
43.718
80.868
124.586
2,255.20
49.904
190.326
240.230
2,255.70
55.404
327.110
382.514
2,256.20
60.405
486.558
546.963
2,256.70
65.023
665.812
730.835
2,257.20
69.334
862.884
932.218
2,257.30
70.165
904.340
974.505
Printed 04-08-2011
9
Stru
#
SWS
#
#1
1

Time of
Conc
SWS Area
(ac)
Musk K
(hrs)
(hrs)
133.640
0.219
Curve
Musk X
0.000
UHS
Number
0.000
86.200
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
886.77
96.080
886.77
96.080
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
133.640
Stru
#
SWS
#
#1
1

Filename: NewS7.sc4
Soil K
0.145
L (ft)
650.00
S (%)
2.00
C
0.3510
P
1.0000
PS #
1
Sediment
(tons)
(ml/l)
1,383.0
19,981
4.39
2.31
1,383.0
19,981
4.39
2.31
Printed 04-08-2011
1
Nkamouna ESCP
Sediment Pond S8
J. Kunkel
Filename: NewS8.sc4
Printed 04-08-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Filename: NewS8.sc4
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 04-08-2011
3
Type
Stru
#
Pond
#1
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
Description
#1
Pond
Filename: NewS8.sc4
Printed 04-08-2011
4
Structure Summary:
#1
In
Out
Filename: NewS8.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
77.220
77.220
Peak
Discharge
(cfs)
Total
Runoff
Volume
(ac-ft)
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
408.24
55.59
766.5
18,811
2.67
1.43
313.33
53.91
631.5
12,878
0.19
0.14
Printed 04-08-2011
5
Structure #1:
Size (mm)
Filename: NewS8.sc4
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
100.000%
100.000%
0.1490
100.000%
100.000%
0.0740
97.490%
100.000%
0.0458
96.117%
100.000%
0.0330
93.096%
100.000%
0.0212
89.389%
100.000%
0.0153
86.093%
100.000%
0.0093
80.052%
97.168%
0.0044
73.186%
88.834%
0.0023
65.909%
80.001%
0.0010
61.103%
74.168%
Printed 04-08-2011
6
Structure Detail:
Structure #1 (Pond)
Sediment Pond S8
Pond Inputs:
Initial Pool Elev:
2,343.10 ft
Initial Pool:
0.23 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Riser
Diameter
(in)
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
5.60
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
6.00
0.0240
2,348.20
250.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
15.00
2,349.20
Pond Results:
Peak Elevation:
2,352.23 ft
2.99 hrs
Pond Model:
CSTRS
Dewater Time:
2.97 days
Trap Efficiency:
17.61 %
Elevation
Filename: NewS8.sc4
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,342.60
0.410
0.000
0.000
Top of Sed. Storage
2,343.10
0.506
0.228
0.000
Low hole SPW #1
2,343.60
0.610
0.507
0.297
11.35*
2,344.10
0.725
0.841
0.420
9.60*
2,344.60
0.850
1.234
0.812
5.87*
2,345.10
0.985
1.692
1.014
5.47*
2,345.60
1.129
2.221
1.476
4.33*
Printed 04-08-2011
Elevation
7
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,346.10
1.283
2.823
1.742
4.55
2,346.60
1.448
3.506
2.262
4.15
2,347.10
1.622
4.273
2.583
3.80
2,347.60
1.807
5.130
3.154
3.65
2,348.10
2.001
6.081
3.522
3.45
2,348.20
2.040
6.283
3.722
0.65
2,348.60
2.203
7.132
7.395
2.10
2,349.10
2.416
8.287
24.952
8.60
Spillway #1
2,349.20
2.460
8.530
29.217
0.55
2,349.60
2.495
9.521
51.994
1.15
Spillway #2
2,350.10
2.540
10.780
86.461
0.60
2,350.60
2.585
12.062
129.445
0.50
2,351.10
2.631
13.366
179.246
0.30
2,351.60
2.676
14.692
234.940
0.25
2,352.10
2.723
16.042
295.911
0.20
2,352.23
2.735
16.408
313.331
0.10 Peak Stage
2,352.50
2.760
17.138
348.170
*Designates time(s) to dewater have been extrapolated beyond the 50 hour hydrograph limit.
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
Filename: NewS8.sc4
2,342.60
0.000
0.000
0.000
2,343.10
2.00>0.000
0.000
0.000
2,343.60
0.297
0.000
0.297
2,344.10
2.00>0.420
0.000
0.420
2,344.60
0.812
0.000
0.812
2,345.10
2.00>1.014
0.000
1.014
2,345.60
1.476
0.000
1.476
2,346.10
2.00>1.742
0.000
1.742
2,346.60
2.262
0.000
2.262
2,347.10
2.00>2.583
0.000
2.583
2,347.60
3.154
0.000
3.154
2,348.10
2.00>3.522
0.000
3.522
2,348.20
3.722
0.000
3.722
2,348.60
7.395
0.000
7.395
2,349.10
24.952
0.000
24.952
2,349.20
29.217
0.000
29.217
2,349.60
40.273
11.721
51.994
Printed 04-08-2011
8
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
Filename: NewS8.sc4
2,350.10
46.916
39.546
86.461
2,350.60
52.729
76.716
129.445
2,351.10
57.961
121.285
179.246
2,351.60
62.759
172.181
234.940
2,352.10
67.215
228.696
295.911
2,352.50
70.577
277.593
348.170
Printed 04-08-2011
9
Stru
#
SWS
#
#1
1

Time of
Conc
SWS Area
(ac)
Musk K
(hrs)
(hrs)
77.220
0.518
Curve
Musk X
0.000
UHS
Number
0.000
86.700
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
408.24
55.586
408.24
55.586
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
77.220
Stru
#
SWS
#
#1
1

Filename: NewS8.sc4
Soil K
0.145
L (ft)
650.00
S (%)
2.00
C
0.4070
P
1.0000
PS #
1
Sediment
(tons)
(ml/l)
766.5
18,811
2.67
1.43
766.5
18,811
2.67
1.43
Printed 04-08-2011
1
Nkamouna ESCP
Sediment Pond S9
J. Kunkel
Filename: NewS9.sc4
Printed 04-08-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Filename: NewS9.sc4
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 04-08-2011
3
Type
Stru
#
(flows
into)
Stru
#
Musk. K
(hrs)
Channel
#1
==>
#2
0.000
0.000 Channel C6
Pond
#2
==>
End
0.000

Musk. X
Description
#1
Chan'l
#2
Pond
Filename: NewS9.sc4
Printed 04-08-2011
4
Structure Summary:
#1
#2
In
Out
Filename: NewS9.sc4
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
67.310
67.310
15.680
82.990
Peak
Discharge
(cfs)
Total
Runoff
Volume
(ac-ft)
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
323.78
50.35
1,231.9
32,707
3.35
1.83
389.48
61.60
1,301.5
29,659
3.25
1.69
367.22
61.60
1,183.4
24,931
1.06
0.66
Printed 04-08-2011
5
Structure #1 (Channel C6):
Size (mm)
In/Out
9.5200
100.000%
4.7600
100.000%
2.0000
100.000%
0.8400
100.000%
0.4200
100.000%
0.2460
100.000%
0.1490
100.000%
0.0740
100.000%
0.0458
100.000%
0.0330
98.823%
0.0212
94.888%
0.0153
91.389%
0.0093
84.976%
0.0044
77.688%
0.0023
69.963%
0.0010
64.862%
Structure #2:
Size (mm)
Filename: NewS9.sc4
In
Out
9.5200
100.000%
100.000%
4.7600
100.000%
100.000%
2.0000
100.000%
100.000%
0.8400
100.000%
100.000%
0.4200
100.000%
100.000%
0.2460
99.722%
100.000%
0.1490
99.426%
100.000%
0.0740
99.118%
100.000%
0.0458
99.055%
100.000%
0.0330
97.803%
100.000%
0.0212
93.908%
100.000%
0.0153
90.446%
99.474%
Printed 04-08-2011
6
Size (mm)
Filename: NewS9.sc4
In
Out
0.0093
84.099%
92.493%
0.0044
76.886%
84.561%
0.0023
69.241%
76.152%
0.0010
64.192%
70.599%
Printed 04-08-2011
7
Structure Detail:
Channel C6
Material: Riprap
Bottom
Width (ft)
Left
Sideslope
Ratio
12.14
Right
Sideslope
Ratio
2.0:1
2.0:1
Slope (%)
Freeboard
Freeboard
Depth (ft)
% of Depth
0.8
Freeboard
Mult. x
(VxD)
1.00
PADER Method - Mild Slope Design
w/o Freeboard
w/ Freeboard
Design Discharge:
323.78 cfs
Depth:
2.87 ft
3.87 ft
Top Width:
23.61 ft
27.61 ft
Velocity:
6.32 fps
X-Section Area:
51.26 sq ft
Hydraulic Radius:
2.053 ft
Froude Number:
0.76
Manning's n:
0.0330
Dmin:
2.00 in
D50:
3.00 in
Dmax:
4.50 in
Structure #2 (Pond)
Sediment Pond S9
Pond Inputs:
Initial Pool Elev:
2,330.50 ft
Initial Pool:
0.00 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
Perforated Riser
Filename: NewS9.sc4
Printed 04-08-2011
Riser
Diameter
(in)
8
Barrel
Diameter
(in)
Riser Height
(ft)
36.00
12.10
Barrel
Length (ft)
36.00
Barrel Slope
(%)
Manning's n
Spillway Elev
(ft)
6.00
0.0240
2,341.60
250.00
Number of
Holes per
Elev
4
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
25.00
2,342.60
Pond Results:
Peak Elevation:
2,345.09 ft
1.62 hrs
Pond Model:
CSTRS
Dewater Time:
0.99 days
Trap Efficiency:
9.08 %
Elevation
Filename: NewS9.sc4
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,329.50
0.000
0.000
0.000
2,330.00
0.002
0.000
0.000
Top of Sed. Storage
2,330.50
0.008
0.003
0.000
2,331.00
0.018
0.009
0.297
1.05
2,331.50
0.031
0.021
0.420
0.40
2,332.00
0.049
0.041
0.812
0.45
2,332.50
0.071
0.071
1.014
0.35
2,333.00
0.096
0.112
1.476
0.45
2,333.50
0.125
0.167
1.742
0.40
2,334.00
0.158
0.238
2.262
0.40
2,334.50
0.195
0.326
2.583
0.45
2,335.00
0.236
0.434
3.154
0.45
2,335.50
0.281
0.563
3.522
0.50
2,336.00
0.330
0.716
4.139
0.45
2,336.10
0.340
0.750
4.227
0.10
2,336.50
0.379
0.893
4.551
0.40
2,337.00
0.430
1.095
5.210
0.50
2,337.50
0.485
1.324
5.663
0.55
2,338.00
0.543
1.581
6.361
0.50
Low hole SPW #1
Printed 04-08-2011
Elevation
9
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
2,338.50
0.604
1.868
6.852
0.50
2,339.00
0.669
2.186
7.586
0.55
2,339.50
0.737
2.537
8.112
0.55
2,340.00
0.808
2.923
8.881
0.55
2,340.50
0.882
3.346
9.441
0.55
2,341.00
0.960
3.806
10.243
0.65
2,341.50
1.041
4.307
10.834
0.70
2,341.60
1.058
4.412
11.078
0.25
2,342.00
1.125
4.848
11.668
3.65
2,342.50
1.212
5.432
24.942
4.65
2,342.60
1.230
5.554
29.217
0.65
2,343.00
1.292
6.059
59.786
1.20
2,343.50
1.372
6.725
112.795
0.95
2,344.00
1.455
7.431
180.553
0.35
2,344.50
1.540
8.180
260.062
0.20
2,345.00
1.627
8.972
349.681
0.20
2,345.09
1.644
9.120
367.217
0.15 Peak Stage
2,345.50
1.717
9.807
448.324
2,345.90
1.790
10.508
533.179
Spillway #1
Spillway #2
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
Filename: NewS9.sc4
2,329.50
0.000
0.000
0.000
2,330.00
0.000
0.000
0.000
2,330.50
2.00>0.000
0.000
0.000
2,331.00
0.297
0.000
0.297
2,331.50
2.00>0.420
0.000
0.420
2,332.00
0.812
0.000
0.812
2,332.50
2.00>1.014
0.000
1.014
2,333.00
1.476
0.000
1.476
2,333.50
2.00>1.742
0.000
1.742
2,334.00
2.262
0.000
2.262
2,334.50
2.00>2.583
0.000
2.583
2,335.00
3.154
0.000
3.154
2,335.50
2.00>3.522
0.000
3.522
2,336.00
4.139
0.000
4.139
2,336.10
4.227
0.000
4.227
Printed 04-08-2011
10
Combined
Elevation
(ft)
crested Weir
(cfs)
Total
Discharge
(cfs)
2,336.50
Filename: NewS9.sc4
2.00>4.551
0.000
4.551
2,337.00
5.210
0.000
5.210
2,337.50
2.00>5.663
0.000
5.663
2,338.00
6.361
0.000
6.361
2,338.50
2.00>6.852
0.000
6.852
2,339.00
7.586
0.000
7.586
2,339.50
2.00>8.112
0.000
8.112
2,340.00
8.881
0.000
8.881
2,340.50
2.00>9.441
0.000
9.441
2,341.00
10.243
0.000
10.243
2,341.50
2.00>10.834
0.000
10.834
2,341.60
11.078
0.000
11.078
2,342.00
11.668
0.000
11.668
2,342.50
24.942
0.000
24.942
2,342.60
29.217
0.000
29.217
2,343.00
40.269
19.517
59.786
2,343.50
46.913
65.882
112.795
2,344.00
52.726
127.827
180.553
2,344.50
57.959
202.103
260.062
2,345.00
62.757
286.924
349.681
2,345.50
67.213
381.111
448.324
2,345.90
70.575
462.604
533.179
Printed 04-08-2011
11
Stru
#
SWS
#
#1
(ac)
1
Musk K
(hrs)
(hrs)
67.310

#2
Time of
Conc
SWS Area
0.655
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
323.78
50.346
323.78
50.346
108.44
11.251
389.48
61.597
Peak
Sediment
Conc.
Peak
Settleable
Conc
24VW
(mg/l)
(ml/l)
67.310
1
15.680

0.170
0.000
0.000
85.000
M
82.990
Stru
#
SWS
#
#1
Soil K
1
0.145
L (ft)
650.00
S (%)
2.00
C
0.7870
P
1.0000
PS #
1

#2
1

Filename: NewS9.sc4
0.145
425.00
2.00
0.2180
1.0000
1
Sediment
(tons)
(ml/l)
1,231.9
32,707
3.35
1.83
1,231.9
32,707
3.35
1.83
69.6
8,607
2.02
1.06
1,301.5
29,659
3.25
1.69
Printed 04-08-2011
1
Nkamouna ESCP
Generic Sediment Trap for Haul Roads
J. Kunkel
Knight Piesold
Filename: Generic Sediment Trap.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
2 yr - 24 hr
Rainfall Depth:
5.100 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
Pond
#1
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
Description
0.000 Sediment Trap
#1
Pond
Printed 03-22-2011
4
Structure Summary:
#1
In
Out
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
5.000
Peak
Discharge
(cfs)
5.000
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
19.14
1.88
23.7
16,711
5.31
2.92
20.56
1.88
15.9
11,822
1.07
0.56
Printed 03-22-2011
5
Structure #1:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
99.800%
100.000%
2.0000
94.800%
100.000%
0.8400
89.000%
100.000%
0.4200
85.200%
100.000%
0.2460
80.600%
100.000%
0.1490
75.900%
100.000%
0.0740
71.000%
100.000%
0.0458
70.000%
100.000%
0.0330
67.800%
100.000%
0.0212
65.100%
96.610%
0.0153
62.700%
93.049%
0.0093
58.300%
86.519%
0.0044
53.300%
79.099%
0.0023
48.000%
71.233%
0.0010
44.500%
66.039%
Printed 03-22-2011
6
Structure Detail:
Structure #1 (Pond)
Sediment Trap
Pond Inputs:
Initial Pool Elev:
2,204.00 ft
Initial Pool:
0.04 ac-ft
*Sediment Storage:
0.00 ac-ft
Dead Space:
20.00 %
*Sediment capacity based on Average Annual R of 0.0 for 0 year(s)
Broad-crested Weir
Weir Width
(ft)
Spillway Elev
(ft)
10.00
2,204.00
Pond Results:
Peak Elevation:
2,204.74 ft
0.02 hrs
Pond Model:
CSTRS
Dewater Time:
0.52 days
Trap Efficiency:
32.62 %
Elevation
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
2,200.00
0.000
0.000
0.000
2,200.50
0.000
0.000
0.000
2,201.00
0.002
0.001
0.000
2,201.50
0.004
0.002
0.000
2,202.00
0.007
0.005
0.000
2,202.50
0.011
0.009
0.000
2,203.00
0.016
0.016
0.000
2,203.50
0.021
0.025
0.000
2,204.00
0.028
0.037
0.000
2,204.50
0.035
0.053
10.914
2,204.74
0.039
0.062
20.560
2,205.00
0.043
0.073
30.870
2,205.50
0.053
0.096
56.712
Dewater
Time
(hrs)
Top of Sed. Storage
Spillway #1
12.00
0.40 Peak Stage
Printed 03-22-2011
Elevation
2,206.00
7
Area
Capacity
Discharge
(ac)
(ac-ft)
(cfs)
0.063
0.125
Dewater
Time
(hrs)
87.314
Combined
Elevation
(ft)
Broadcrested Weir
(cfs)
Total
Discharge
(cfs)
2,200.00
0.000
0.000
2,200.50
0.000
0.000
2,201.00
0.000
0.000
2,201.50
0.000
0.000
2,202.00
0.000
0.000
2,202.50
0.000
0.000
2,203.00
0.000
0.000
2,203.50
0.000
0.000
2,204.00
0.000
0.000
2,204.50
10.914
10.914
2,205.00
30.870
30.870
2,205.50
56.712
56.712
2,206.00
87.314
87.314
Printed 03-22-2011
8
Stru
#
SWS
#
#1
(ac)
1
Σ
Time of
Conc
SWS Area
Musk K
(hrs)
(hrs)
5.000
0.083
Curve
Musk X
0.000
UHS
Number
0.000
95.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
5.000
19.14
1.881
19.14
1.881
Stru
#
SWS
#
#1
1
Soil K
0.146
L (ft)
75.00
Σ
S (%)
2.00
C
1.0000
P
1.0000
PS #
1
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc
(mg/l)
(ml/l)
24VW
(ml/l)
23.7
16,711
5.31
2.92
23.7
16,711
5.31
2.92
Printed 03-22-2011
1
Nkamouna ESCP
GenericGrass
Silt Fence
Generic
Filterfor
forBox
BoxCut
CutReclamation
Reclamation
J. Kunkel
Knight Piesold
Filename: Generic Silt Fence.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
Silt Fence
#3
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
0.000
Description
Generic Silt Fence for Box Cut
Reclamation
#3
Silt
Fence
Printed 03-22-2011
4
Structure Summary:
#3
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
In
Out
1.000
Peak
Discharge
(cfs)
1.000
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
9.43
0.94
17.7
25,044
7.96
4.37
8.74
0.94
9.2
14,970
0.00
0.00
Printed 03-22-2011
5
Structure #3:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
99.800%
100.000%
2.0000
94.800%
100.000%
0.8400
89.000%
100.000%
0.4200
85.200%
100.000%
0.2460
80.600%
100.000%
0.1490
75.900%
100.000%
0.0740
71.000%
100.000%
0.0458
70.000%
100.000%
0.0330
67.800%
100.000%
0.0212
65.100%
100.000%
0.0153
62.700%
100.000%
0.0093
58.300%
100.000%
0.0044
53.300%
100.000%
0.0023
48.000%
92.031%
0.0010
44.500%
85.321%
Printed 03-22-2011
6
Structure Detail:
Structure #3 (Silt Fence)
Generic Silt Fence for Box Cut Reclamation
Silt Fence Inputs:
Fence Flow
Rate (gpm/sq
ft)
Width along
contour (ft)
10.0
Land Slope
(%)
Height (ft)
444.0
3.0
Tie-back
distance (ft)
4.00
75.0
*Sediment Storage: 0.00 ac-ft
Silt Fence Results:
Peak Fence Stage:
0.84 ft
Peak Water Stage:
0.84 ft
Dewater Time:
0.50 days
Trap Efficiency:
47.84 %
Stage-Capacity-Discharge Table
Fence Stage
Water Stage
Area
Capacity
Discharge
(ft)
(ft)
(ac)
(ac-ft)
(cfs)
Dewater
Time
(hrs)
0.00
0.00
0.000
0.000
0.000
0.10
0.10
0.025
0.001
0.995
11.40
0.20
0.20
0.051
0.005
2.001
0.20
0.30
0.30
0.076
0.011
3.018
0.15
0.40
0.40
0.102
0.020
4.046
0.05
0.50
0.50
0.127
0.031
5.086
0.05
0.60
0.60
0.153
0.045
6.136
0.05
0.70
0.70
0.178
0.062
7.198
0.05
0.80
0.80
0.204
0.081
8.271
0.84
0.84
0.215
0.090
8.744
0.90
0.90
0.229
0.103
9.355
1.00
1.00
0.255
0.127
10.450
1.10
1.10
0.280
0.154
11.556
1.20
1.20
0.306
0.183
12.674
1.30
1.30
0.331
0.215
13.802
1.40
1.40
0.357
0.249
14.942
1.50
1.50
0.382
0.286
16.093
1.60
1.60
0.408
0.326
17.255
1.70
1.70
0.433
0.368
18.428
Top of Sediment
0.01 Peak Stage
Printed 03-22-2011
7
Fence Stage
Water Stage
Area
Capacity
Discharge
(ft)
(ft)
(ac)
(ac-ft)
(cfs)
1.80
1.80
0.459
0.412
19.612
1.90
1.90
0.484
0.459
20.808
2.00
2.00
0.510
0.509
22.014
2.10
2.10
0.535
0.561
23.232
2.20
2.20
0.561
0.616
24.461
2.30
2.30
0.586
0.673
25.701
2.40
2.40
0.612
0.733
26.952
2.50
2.50
0.637
0.796
28.214
2.60
2.60
0.663
0.861
29.488
2.70
2.70
0.688
0.928
30.772
2.80
2.80
0.713
0.998
32.068
2.90
2.90
0.739
1.071
33.375
3.00
3.00
0.764
1.146
34.693
Dewater
Time
(hrs)
Printed 03-22-2011
8
Stru
#
SWS
#
#3
(ac)
1
Σ
Time of
Conc
SWS Area
Musk K
(hrs)
(hrs)
1.000
0.083
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
1.000
9.43
0.938
9.43
0.938
Stru
#
SWS
#
#3
1
Soil K
0.145
Σ
L (ft)
98.00
S (%)
4.00
C
0.7870
P
1.0000
PS #
1
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc
(mg/l)
(ml/l)
24VW
(ml/l)
17.7
25,044
7.96
4.37
17.7
25,044
7.96
4.37
Printed 03-22-2011
1
Nkamouna ESCP
Generic Grass Filter for Box Cut Reclamation
J. Kunkel
Knight Piesold
Filename: Generic Grass Filter.sc4
Printed 03-22-2011
2
General Information
Storm Information:
Storm Type:
NRCS Type II
Design Storm:
25 yr - 24 hr
Rainfall Depth:
12.500 inches
Size (mm)
Average PSD
9.5200
100.000%
4.7600
99.800%
2.0000
94.800%
0.8400
89.000%
0.4200
85.200%
0.2460
80.600%
0.1490
75.900%
0.0740
71.000%
0.0458
70.000%
0.0330
67.800%
0.0212
65.100%
0.0153
62.700%
0.0093
58.300%
0.0044
53.300%
0.0023
48.000%
0.0010
44.500%
Printed 03-22-2011
3
Type
Stru
#
Grass Filter
#2
(flows
into)
==>
Stru
#
End
Musk. K
(hrs)
0.000
Musk. X
0.000
Description
Generic Grass Filter for Box Cut
Reclamation
#2
Grass
Filter
Printed 03-22-2011
4
Structure Summary:
#2
In
Out
Immediate
Contributing
Area
Total
Contributing
Area
(ac)
(ac)
1.000
Peak
Discharge
(cfs)
1.000
Total
Runoff
Volume
Sediment
(tons)
(ac-ft)
Peak
Sediment
Conc.
Peak
Settleable
Conc.
(mg/l)
(ml/l)
24VW
(ml/l)
9.43
0.94
17.7
25,044
7.96
4.37
8.42
0.38
6.7
14,335
0.00
0.00
Printed 03-22-2011
5
Structure #2:
Size (mm)
In
Out
9.5200
100.000%
100.000%
4.7600
99.800%
100.000%
2.0000
94.800%
100.000%
0.8400
89.000%
100.000%
0.4200
85.200%
100.000%
0.2460
80.600%
100.000%
0.1490
75.900%
100.000%
0.0740
71.000%
100.000%
0.0458
70.000%
100.000%
0.0330
67.800%
100.000%
0.0212
65.100%
100.000%
0.0153
62.700%
100.000%
0.0093
58.300%
100.000%
0.0044
53.300%
100.000%
0.0023
48.000%
94.794%
0.0010
44.500%
87.965%
Printed 03-22-2011
6
Structure Detail:
Structure #2 (Grass Filter)
Generic Grass Filter for Box Cut Reclamation
Grass Filter Inputs:
Roughness
Coefficient
Grass Height
(in)
Hydraulic
Spacing (in)
11.8
0.96
0.0117
Infiltration
Rate (iph)
1.00
Stiffness
Factor
(N-sq m)
100.000
Filter Length
(ft)
98.0
Filter Width
(ft)
444.0
Filter Slope
(%)
4.0
Grass Filter Results:
Total Infiltration Volume:
0.5582 ac-ft
Filter Infiltration Rate:
1.0072 cfs
Peak Flow Depth:
0.196 in
Critical Prone Velocity:
1.2295 fps
Wedge Location:
0.86 ft
Sediment Depth in Zone D:
0.0248 in
Trap Efficiency:
62.0 %
Printed 03-22-2011
7
Stru
#
SWS
#
#2
(ac)
1
Σ
Time of
Conc
SWS Area
Musk K
(hrs)
(hrs)
1.000
0.083
Curve
Musk X
0.000
UHS
Number
0.000
90.000
Peak
Discharge
Runoff
Volume
(cfs)
(ac-ft)
M
1.000
9.43
0.938
9.43
0.938
Stru
#
SWS
#
#2
1
Soil K
0.145
L (ft)
98.00
Σ
S (%)
4.00
C
0.7870
P
1.0000
PS #
1
Sediment
(tons)
Peak
Sediment
Conc.
Peak
Settleable
Conc
(mg/l)
(ml/l)
24VW
(ml/l)
17.7
25,044
7.96
4.37
17.7
25,044
7.96
4.37
Printed 03-22-2011

Erosion and Sediment Control

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