Bathymetric and Sediment Survey of Lovewell Reservoir, Jewell

Bathymetric and Sediment Survey of
Lovewell Reservoir, Jewell County, Kansas
Kansas Biological Survey
Applied Science and Technology for
Reservoir Assessment (ASTRA) Program
Report 2012-01 (April 2013)
This work was funded by the Kansas Water Office through the State
Water Plan Fund in support of the Reservoir Sustainability Initiative.
SUMMARY
In July 2011, the Kansas Biological Survey (KBS) performed a bathymetric survey of
Lovewell Reservoir in Jewell County, Kansas. The survey was carried out using acoustic
echosounding apparatus linked to a global positioning system. The 2011 bathymetric survey by
KBS indicated that the area of the active pool at 1583.6 ft was 2820 acres with a capacity of
36,038 acre-feet.
Fourteen sediment cores were extracted from the lake to determine accumulated sediment
thickness at locations distributed across the reservoir. Sediment samples were taken from the top
six inches of each core and analyzed for particle size distributions.
Summary Data:
Bathymetric Survey:
Dates of survey:
Water elevation on date(s) of survey:
Reservoir Statistics:
Elevation of pool on reference date
(NAIP photography, 2008)
Area at 1582.6 active pool:
Volume at 1582.6 active pool:
July 13, 2011
July 14, 2011
July 15, 2011
(see text)
1583.6 ft.
2820 acres
36,038 acre-feet
Maximum depth at 1582.6 active pool:
29 ft.
Year constructed (gates closed):
1956
Datums
UTM Zone:
UTM datum:
Vertical datum, all data:
14N
NAD83
NGVD29
Sediment Survey:
Date of sediment survey:
August 9, 2012
TABLE OF CONTENTS
SUMMARY.....................................................................................................................i
TABLE OF CONTENTS................................................................................................ii
LIST OF FIGURES....................................................................................................... iii
LIST OF TABLES ........................................................................................................iv
LAKE HISTORY AND PERTINENT INFORMATION .................................................. 1
BATHYMETRIC SURVEYING PROCEDURE
Pre-survey preparation:..................................................................................... 3
Survey procedures: ........................................................................................... 3
Establishment of lake level on survey date: ...................................................... 4
Post-processing ................................................................................................ 6
BATHYMETRIC SURVEY RESULTS
Area-volume-elevation tables............................................................................ 9
RESERVOIR CROSS-SECTIONS ............................................................................. 12
SEDIMENT CORING AND SAMPLING..................................................................... 19
Sediment coring and sampling results........................................................................ 20
ii
LIST OF FIGURES
Figure 1.
Lovewell Reservoir . ................................................................................. 1
Figure 2.
Location of Lovewell Reservoir in Jewell County, Kansas. ....................... 2
Figure 3.
Bathymetric survey transects. ................................................................... 5
Figure 4.
Reservoir depth map ................................................................................ 8
Figure 5.
Cumulative area-elevation curve. ........................................................... 11
Figure 6.
Cumulative volume-elevation curve. ....................................................... 11
Figure 7.
Cross-section lines map ......................................................................... 13
Figure 8.
Cross-sections along range lines:
8a. Cross-section along Line 1 .............................................................. 14
8b. Cross-section along Line 2 .............................................................. 14
8c. Cross-section along Line 3............................................................... 15
8d. Cross-section along Line 4 .............................................................. 15
8e. Cross-section along Line 5 .............................................................. 16
8f. Cross-section along Line 6 ............................................................... 16
8g. Cross-section along Line 7 .............................................................. 17
8h. Cross-section along Line 8 .............................................................. 17
Figure 9.
Sediment coring sites in Lovewell Reservoir........................................... 21
Figure 10. Map of sediment thickness in centimeters at coring sites ....................... 22
Figure 11. Sediment particle size analysis. .............................................................. 24
Figure 12. Map of sediment particle size distributions at coring sites ....................... 25
Figure 13. Total nitrogen (ppm) from sediment chronosequence of core
LOVE-4 ................................................................................................... 26
Figure 14. Total phosphorus (ppm) from sediment chronosequence of core
LOVE-4 ................................................................................................... 27
iii
LIST OF TABLES
Table 1.
Cumulative area in acres by tenth foot elevation increments................... 9
Table 2.
Cumulative volume in acre-feet by tenth foot elevation
increments .............................................................................................. 10
Table 3.
Cross-section endpoint coordinates........................................................ 12
Table 4.
Bureau of Reclamation and KBS 2011 area and capacity data .............. 18
Table 5
Lovewell Reservoir sediment coring site data......................................... 23
iv
Figure 1. Lovewell Reservoir and Dam in Jewell County, Kansas.
The following text was obtained from the US Bureau of Reclamation website,
http://www.usbr.gov/projects/Project.jsp?proj_Name=Bostwick Division.
Lovewell Dam is on the White Rock Creek 3 miles northwest of Lovewell, Kansas. The
reservoir stores water from White Rock Creek and diversions from the Republican River
by way of the Courtland Canal. The dam is a 3-million-cubic-yard earthfill structure,
8,500 feet long, with a height-of-embankment 81 feet above streambed. The total
capacity of the reservoir is 92,150 acre-feet, of which 24,930 is allocated for
conservation, 50,460 acre-feet for flood control, and the remainder for inactive and dead
capacity.
The dam and reservoir are part of the Bureau of Reclamation's Bostwick Division. The
Bostwick Division is in south-central Nebraska and north-central Kansas. It extends
from Orleans, Nebraska, above Harlan County Lake, to Norway, Kansas, and includes
land on both sides of the Republican River. The reservoir, lake, and surrounding lands
of the division provide benefits for flood control, irrigation, sediment control, fish and
wildlife enhancement, and recreation.
1
Jewell County, Kansas
¬
«
K128
Webber
¬
«
K14
Burr Oak
Esbon
£
¤
¬
«
36
K112
Mankato
Formoso
¬
«
K128
Jewell
¬
«
¬
«
K148
K228
Randall
¬
«
K28
0
2.5
5
Figure 2. Location of Lovewell Reservoir in Jewell County, Kansas
2
Miles
10
Reservoir Bathymetric (Depth) Surveying Procedures
KBS operates a Biosonics DT-X echosounding system (www.biosonicsinc.com) with a
200 kHz split-beam transducer and a 38-kHz single-beam transducer. Latitudelongitude information is provided by a global positioning system (GPS) that interfaces
with the Biosonics system. ESRI’s ArcGIS is used for on-lake navigation and
positioning, with GPS data feeds provided by the Biosonics unit through a serial cable.
Power is provided to the echosounding unit, command/navigation computer, and
auxiliary monitor by means of a inverter and battery backup device that in turn draw
power from the 12-volt boat battery.
Pre-survey preparation:
Geospatial reference data: Prior to conducting the survey, geospatial data of the target
lake is acquired, including georeferenced National Agricultural Imagery Project (NAIP)
photography. The lake boundary is digitized as a polygon shapefile from the FSA NAIP
georeferenced aerial photography obtained online from the Data Access and Service
Center (DASC). Prior to the lake survey, a series of transect lines are created as a
shapefile in ArcGIS for guiding the boat during the survey. A transect spacing of 100
meters was used for the main body of the reservoir, narrowing this distance as needed
in smaller coves and inlets.
Survey procedures:
Calibration (Temperature and ball check): After boat launch and initialization of the
Biosonics system and command computer, system parameters are set in the Biosonics
Visual Acquisition software. The temperature of the lake at 1-2 meters is taken with a
research-grade metric electronic thermometer. This temperature, in degrees Celsius, is
input to the Biosonics Visual Acquisition software to calculate the speed of sound in
water at the given temperature at the given depth. Start range, end range, ping
duration, and ping interval are also set at this time. A ball check is performed using a
tungsten-carbide sphere supplied by Biosonics for this purpose. The ball is lowered to a
known distance (1.0 meter) below the transducer faces. The position of the ball in the
water column (distance from the transducer face to the ball) is clearly visible on the
echogram. The echogram distance is compared to the known distance to assure that
parameters are properly set and the system is operating correctly.
On-lake survey procedures: Using the GPS Extension of ArcGIS, the GPS data feed
from the GPS receiver via the Biosonics echosounder, and the pre-planned transect
pattern, the location of the boat on the lake in real-time is shown on the
command/navigation computer screen. Transducer face depth on all dates is 0.25
meters below the water surface. A perimeter run is initially performed to set the
immediate off-shore water depth, with this survey track typically placed 50 meters from
shore, modified as necessary during the survey if shallow water or other obstructions
are encountered. Following the perimeter run, the cross-lake transects are then
acquired. The transect pattern is maintained except when modified by obstructions in
the lake (e.g., partially submerged trees) or shallow water and mudflats. Data are
automatically logged in new files every half-hour (approximately 9000-ping files) by the
Biosonics system.
3
Establishment Of Lake Level On Survey Dates:
Reservoir shoreline perimeters were digitized off 2008 NAIP aerial photography and the
elevation of the reservoir on the date of aerial photography was used as the water
surface elevation in all interpolations from point data to raster data. The water elevation
on July 11, 2008 was 1583.69 feet AMSL, NGVD29.
Lake levels on the survey dates were obtained from the Bureau of Reclamation
HYDROMET database at http://www.usbr.gov/gp-bin/arc050_form.pl?LVKS
Lake level on survey dates
Survey Date
Elevation (feet)
July 13, 2011
1586.12
July 14, 2011
1586.04
July 15, 2011
1585.91
Water surface elevations for each date of survey were used to convert relative water
depths on each date to absolute measures of reservoir bottom depth at each point.
4
5
Figure 3. Bathymetric survey transects, July 2011
7/15/2011
7/14/2011
7/13/2011
Survey Date
0
0.25
0.5
1
Miles
Ü
Post-processing (Visual Bottom Typer)
The Biosonics DT-X system produces data files in a proprietary DT4 file format
containing acoustic and GPS data. To extract the bottom position from the acoustic
data, each DT4 file is processed through the Biosonics Visual Bottom Typer (VBT)
software. The processing algorithm is described as follows:
“The BioSonics, Inc. bottom tracker is an “end_up" algorithm, in that
it begins searching for the bottom echo portion of a ping from the last
sample toward the first sample. The bottom tracker tracks the bottom echo
by isolating the region(s) where the data exceeds a peak threshold for N
consecutive samples, then drops below a surface threshold for M samples.
Once a bottom echo has been identified , a bottom sampling window is
used to find the next echo. The bottom echo is first isolated by user_defined
threshold values that indicate (1) the lowest energy to include in the bottom
echo (bottom detection threshold) and (2) the lowest energy to start looking
for a bottom peak (peak threshold). The bottom detection threshold allows
the user to filter out noise caused by a low data acquisition threshold. The
peak threshold prevents the algorithm from identifying the small energy
echoes (due to fish, sediment or plant life) as a bottom echo.” (Biosonics
Visual Bottom Typer User’s Manual, Version 1.10, p. 70).
Data is output as a comma-delimited (*.csv) text file. A set number of qualifying pings
are averaged to produce a single report (for example, the output for ping 31 {when
pings per report is 20} is the average of all values for pings 12-31). Standard analysis
procedure for all 2008 and later data is to use the average of 5 pings to produce one
output value. All raw *.csv files are merged into one master *.csv file using the
shareware program File Append and Split Tool (FAST) by Boxer Software (Ver. 1.0,
2006).
Post-processing (Excel)
The master *.csv file created by the FAST utility is imported into Microsoft Excel.
Excess header lines are deleted (each input CSV file has its own header), and the
header file is edited to change the column headers “#Ping” to “Ping” and “E1’ “ to “E11”,
characters that are not ingestable by ArcGIS. Entries with depth values of zero (0) are
deleted, as are any entries with depth values less than the start range of the data
acquisition parameter (0.49 meters or less) (indicating areas where the water was too
shallow to record a depth reading).
In Excel, depth adjustments are made. A new field – Adj_Depth – is created. The value
for AdjDepth is calculated as AdjDepth = Depth + (Transducer Face Depth), where the
Transducer Face Depth represents the depth of the transducer face below water level in
meters (Typically, this value is 0.2 meters; however, if changes were made in the field,
the correct level is taken from field notes and applied to the data). Depth in feet is also
calculated as DepthFt = Adj_Depth * 3.28084.
6
These water depths are RELATIVE water depths that can vary from day-to-day based
on the elevation of the water surface. In order to normalize all depth measurements to
an absolute reference, water depths must be subtracted from an established value for
the elevation of the water surface at the time of the bathymetric survey. Determination
of water surface elevation has been described in an earlier section on establishment of
lake levels.
To set depths relative to lake elevation, two additional fields are added to the attribute
table of the point shapefile: LakeElevM, the reference surface elevation (the elevation of
the water surface on the day that the aerial photography from which the lake perimeter
polygon was digitized)and Elev_Ft, the elevation of the water surface in feet above sea
level (Elev_ft), computed by converting ElevM to elevation in feet (ElevM * 3.28084).
Particularly for multi-day surveys, Adj_Depth and Depth_Ft should NOT be used for
further analysis or interpolation. If water depth is desired, it should be produced by
subtracting Elev_M or Elev_Ft from the reference elevation used for interpolation
purposes (for federal reservoirs, the elevation of the water surface on the day that the
aerial photography from which the lake perimeter polygon was digitized).
Post-processing (ArcGIS):
Ingest to ArcGIS is accomplished by using the Tools – Add XY Data option. The
projection information is specified at this time (WGS84). Point files are displayed as
Event files, and are then exported as a shapefile (filename convention:
ALLPOINTS_WGS84.shp). The pointfile is then reprojected to the UTM coordinate
system of the appropriate zone (14 or 15) (filename convention ALLPOINTS_UTM.shp).
Raster interpolation of the point data is performed using the same input data and the
Topo to Raster option within the 3D Extension of ArcGIS. The elevation of the reservoir
on the date of aerial photography used to create the perimeter/shoreline shapefile was
used as the water surface elevation in all interpolations from point data to raster data.
Contour line files are derived from the raster interpolation files using the ArcGIS
command under 3D Analyst – Raster Surface – Contour.
Area-elevation-volume tables are derived using an ArcGIS extension custom written for
and available from the ASTRA Program. Summarized, the extension calculates the
area and volume of the reservoir at 1/10-foot elevation increments from the raster data
for a series of water surfaces beginning at the lowest elevation recorded and
progressing upward in 1/10-foot elevation increments to the reference water surface.
Cumulative volume is also computed in acre-feet.
7
8
Figure 4. Depth map from KBS bathymetric survey for Lovewell Reservoir.
(Depths based on pool elevation 1583.69 ft. AMSL NGVD29).
30.01 - 35
25.01 - 30
20.01 - 25
15.01 - 20
10.01 - 15
5.01 - 10
0-5
Depth in Feet
0
0.25
0.5
1
Miles
Ü
Table 1
Cumulative area in acres by tenth foot elevation increments
Elevation (ft
NGVD)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1550
0
0
0
0
0
0
0
0
0
0
1551
0
0
0
0
0
0
0
0
0
0
1552
0
0
0
0
0
0
0
0
0
0
1553
0
0
0
0
0
1
3
4
5
5
1554
6
6
7
7
8
8
8
9
9
9
1555
10
11
12
13
13
15
17
18
21
22
1556
23
25
28
31
34
38
42
48
56
64
1557
73
80
86
93
100
108
114
121
127
133
1558
140
145
151
156
162
167
173
178
184
190
1559
195
200
206
212
219
225
232
240
248
255
1560
264
273
284
293
304
313
322
332
341
350
1561
360
369
378
388
398
410
422
436
453
468
1562
483
498
510
521
533
546
558
569
581
593
1563
605
617
629
641
653
665
678
690
703
715
1564
726
738
749
760
772
783
794
805
818
832
1565
846
863
878
893
908
921
933
946
958
971
1566
983
996
1009
1022
1035
1047
1060
1072
1084
1095
1567
1107
1118
1128
1138
1148
1159
1169
1178
1188
1197
1568
1207
1216
1225
1234
1243
1252
1260
1269
1277
1286
1569
1295
1303
1313
1321
1330
1338
1347
1355
1364
1372
1570
1380
1388
1397
1405
1413
1421
1430
1438
1447
1456
1571
1465
1474
1483
1493
1502
1511
1521
1531
1541
1553
1572
1565
1578
1591
1605
1618
1632
1646
1659
1672
1686
1573
1698
1711
1724
1736
1750
1765
1779
1794
1808
1822
1574
1836
1850
1864
1879
1894
1910
1926
1943
1958
1973
1575
1987
2001
2014
2029
2042
2055
2068
2080
2093
2106
1576
2119
2132
2144
2157
2170
2184
2199
2213
2231
2249
1577
2266
2282
2298
2313
2329
2343
2358
2372
2386
2399
1578
2414
2428
2442
2456
2469
2482
2494
2506
2517
2528
1579
2540
2553
2564
2575
2585
2595
2605
2615
2624
2633
1580
2641
2649
2657
2665
2672
2680
2687
2694
2701
2708
1581
2715
2722
2728
2735
2742
2750
2756
2763
2769
2776
1582
2782
2789
2795
2801
2807
2814
2820
2826
2832
2838
1583
2845
2851
2857
2863
2870
2876
2882
9
Table 2
Cumulative volume in acre-feet by tenth foot elevation increments
Elevation (ft
NGVD)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1550
0
0
0
0
0
0
0
0
0
0
1551
0
0
0
0
0
0
0
0
0
0
1552
0
0
0
0
0
0
0
0
0
0
1553
0
0
0
0
0
0
0
1
1
2
1554
2
3
3
4
5
6
6
7
8
9
1555
10
11
12
13
15
16
18
19
21
24
1556
26
28
31
34
37
41
45
49
54
60
1557
67
75
83
92
102
112
123
135
147
160
1558
174
188
203
219
234
251
268
285
304
322
1559
342
361
382
403
424
446
469
493
517
542
1560
568
595
623
652
682
713
744
777
811
845
1561
881
917
955
993
1032
1073
1115
1158
1202
1248
1562
1296
1345
1395
1447
1499
1553
1609
1665
1723
1781
1563
1841
1902
1965
2028
2093
2159
2226
2295
2364
2435
1564
2507
2581
2655
2730
2807
2885
2964
3044
3125
3208
1565
3292
3377
3464
3553
3643
3734
3827
3921
4016
4113
1566
4211
4310
4410
4512
4615
4719
4824
4931
5039
5148
1567
5258
5369
5482
5595
5710
5825
5942
6059
6177
6297
1568
6417
6538
6661
6784
6908
7032
7158
7285
7412
7540
1569
7670
7800
7930
8062
8195
8328
8463
8598
8734
8871
1570
9008
9147
9286
9427
9568
9709
9852
9996
10140
10285
1571
10431
10578
10726
10875
11025
11176
11328
11480
11634
11789
1572
11945
12102
12261
12421
12582
12745
12909
13074
13241
13409
1573
13578
13749
13920
14094
14268
14444
14621
14800
14980
15162
1574
15345
15529
15715
15902
16091
16282
16474
16667
16862
17059
1575
17257
17457
17658
17860
18064
18269
18475
18682
18891
19101
1576
19313
19525
19739
19955
20171
20389
20608
20829
21051
21276
1577
21502
21729
21958
22189
22421
22655
22890
23127
23365
23605
1578
23845
24088
24331
24576
24823
25071
25320
25570
25821
26074
1579
26327
26582
26838
27095
27353
27613
27873
28134
28396
28659
1580
28923
29188
29453
29720
29987
30255
30523
30792
31062
31333
1581
31604
31877
32149
32423
32697
32972
33247
33523
33800
34078
1582
34356
34635
34914
35194
35475
35756
36038
36320
36603
36887
1583
37171
37456
37742
38028
38315
38603
38891
10
3500
Cumulative Area (acres)
3000
2500
2000
1500
1000
500
0
1550
1555
1560
1565
1570
1575
1580
1585
1575
1580
1585
Elevation (feet)
Figure 5. Cumulative area-elevation curve
45000
40000
Cumulative Volume (acre-feet)
35000
30000
25000
20000
15000
10000
5000
0
1550
1555
1560
1565
1570
Elevation (feet)
Figure 6. Cumulative volume-elevation curve
11
Reservoir Cross-sections
Eight cross-section lines were digitized as a line shapefile across Lovewell Reservoir.
Each line was converted into a point shapefile with points at 10-meter intervals. The
ArcGIS program Extract Values to Points was used to extract the elevation value for
each point from the reservoir bottom elevation DEM previously described. Points were
then imported to Excel for plotting as charts (Figure 8a – 8h). No data was extracted for
the non-water areas outside the perimeter of the lake digitized from the 2008 NAIP
photography; these values were set to 1583.69 ft. AMSL, NGVD29.
Table 3.
Cross-section endpoint Coordinates (UTM Zone 14)
Line
Start Endpoint
End Endpoint
UTM X
UTM Y
UTM X
UTM Y
1
583169
4417032
582424
4416664
2
583169
4417032
582684
4414947
3
582682
4414941
582232
4416340
4
580184
4414679
581489
4416693
5
579529
4416601
580181
4417884
6
579106
4416461
578581
4417920
7
577776
4416800
577919
4417871
8
577776
4416800
576976
4418676
12
13
6
7
Figure 7. KBS cross-sections for Lovewell Reservoir.
(Depths based on pool elevation 1583.69 ft. AMSL NGVD29).
crossections
30.01 - 35
25.01 - 30
20.01 - 25
15.01 - 20
10.01 - 15
5.01 - 10
0-5
Depth in Feet
0
0.25
0.5
1
1
Miles
Ü
2
8
3
4
5
Cross-section 1
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
Meters along cross-section, east-w est
Figure 8a. Cross-section along Line 1. Reservoir reference elevation = 1583.69 ft.
Cross-section 2
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
1250
1500
1750
Meters along cross-section, south-north
Figure 8b. Cross-section along Line 2. Reservoir reference elevation = 1583.69 ft.
14
2000
Cross-section 3
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
1250
Meters along cross-section, south-north
Figure 8c. Cross-section along Line 3. Reservoir reference elevation = 1583.69 ft.
Cross-section 4
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
1250
1500
1750
2000
Meters along cross-section, south-north
Figure 8d. Cross-section along Line 4. Reservoir reference elevation = 1583.69 ft.
15
2250
Cross-section 5
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
1250
Meters along cross-section, south-north
Figure 8e. Cross-section along Line 5. Reservoir reference elevation = 1583.69 ft.
Cross-section 6
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
1250
Meters along cross-section, south-north
Figure 8f. Cross-section along Line 6. Reservoir reference elevation = 1583.69 ft.
16
1500
Cross-section 7
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
Meters along cross-section, south-north
Figure 8g. Cross-section along Line 7. Reservoir reference elevation = 1583.69 ft.
Cross-section 8
1600
1595
1590
Elevation (feet)
1585
1580
1575
1570
1565
1560
1555
1550
0
250
500
750
1000
1250
1500
1750
Meters along cross-section, south-north
Figure 8h. Cross-section along Line 8. Reservoir reference elevation = 1583.69 ft.
17
2000
Table 4.
US Bureau of Reclamation and KBS 2011 Area and Capacity Data for Lovewell Reservoir
Elevation
Original
Area
(acres)
Original
capacity
(acre-feet)
1995 area
(acres)
1995
capacity
(acre-feet)
2011 area
(acres)
2011
capacity
(acre-feet)
1580.0
2592
34435
2594
28410
2641
28923
1575.0
2020
22905
1892
17194
1987
17257
1570.0
1542
14000
1342
9233
1380
9008
1565.0
1023
7588
864
3642
846
3292
1560.0
484
3820
293
846
264
568
1555.0
266
1945
34
46
10
10
1550.0
164
870
0
0
0
0
1545.0
69
288
0
0
0
0
1540.0
23
58
0
0
0
0
1535.0
0
0
0
0
0
0
Data source for original and 1995 area/capacity: Table 2 in Ferrari, R. 1996. Lovewell
Reservoir, 1995 Sedimentation Study. Sedimentation and River Hydraulics Group, Technical
Service Center, Bureau of Reclamation, Denver Federal Center, P.O. Box 25007 (86-68240)
Denver, CO 80225-0007. 2011 area and capacity rounded to nearest whole number.
18
SEDIMENT CORING/SAMPLING PROCEDURES
KBS operates a Specialty Devices Inc.
sediment vibracorer mounted on a dedicated
24’ pontoon boat. The vibracorer uses 3”
diameter aluminum thinwall pipe in userspecified lengths. The system uses an 24-v
electric motor with counter-rotating weights in
the vibracorer head unit to create a highfrequency vibration in the pipe, allowing the
pipe to penetrate sediments and substrate as it
is lowered into the lake using a winch. Once
the open end of the core pipe has penetrated
to the substrate, the unit is turned off and the
unit is raised to the surface using the winch. At
the surface, the pipe containing the sediment
core is disconnected from the vibracore head
and the sediment extruded from the pipe and
measured.
KBS vibe-core system.
At each site, determined using GPS, the core boat is anchored and the vibracore
system used to extract a sediment core down to and including the upper several inches
of pre-impoundment soil (substrate). The location of each core site is recorded using a
GPS. Cores are carefully extruded from the core pipe, and the interface between
sediment and substrate identified. Typically, this identification is relatively easy, with the
interface being identifiable by changes in material density and color, and the presence
of roots or sticks in the substrate. The top 15 cm of sediment are collected and sealed
in a sampling container. The samples are then shipped to the Kansas State University
Soil Testing Laboratory (Manhattan, KS), for texture and other analyses.
To assess bulk density, the syringe method described by Hilton et al (1986)1 was used,
employing a cutoff 35-ml syringe inserted into the exposed core to extract a 15-cc
sample of the sediment. Where permitted by core length, samples were taken from the
lower, midpoint, and upper parts of the core (e.g., 10-cm above sediment-substrate
interface; midpoint of core length; 10 cm below sediment top). Shorter cores (30-50
cm) were sampled only at the upper and lower end, and very short (length < 20 cm)
were sampled only at the midpoint. Samples were ejected from the syringe using the
plunger and sealed in sample canisters. In the lab, samples were weighed, dried at
100ºC for 48 hours, and weighed again. At several sites, a bulk density sample was
taken from the substrate as well for comparison to sediment bulk density.
1
J. Hilton, J., Lishman, P., and Millington, A. 1986. A comparison of some rapid techniques for
the measurement of density in soft sediments. Sedimentology (33):777-781.
19
Sediment Coring and Sampling Results:
Fourteen coring sites were distributed across the reservoir (Figure 9). An effort was
made to avoid the original stream channel, which would have likely yielded higher
sediment thicknesses not representative of the overall reservoir bottom sediment
thickness. Relatively high sediment thicknesses were recorded near the dam at sites
LOVE-1 (85 cm), LOVE-3 (205 cm) and LOVE-4 (110 cm) (Figure 10; Table 5).
Sediment thickness could not be determined at site LOVE-14 due to indeterminate
interface between sediment and original substrate. Upstream sites in the upper half of
the reservoir recorded little (20-22 cm, sites LOVE-8 and LOVE-9) to no sediment
accumulation (Sites LOVE-10, -11, and -13).
Texture analysis indicated that sediment in the reservoir is predominately silt, with a
secondary fraction of clay. Again, typical of large reservoirs sampled in this area, silt
predominates in the samples taken from the upper (inflow) end, and clay is slightly more
predominant in the samples taken from the lower (dam) end (Figure 12). Sand was a
significant constituent in site LOVE-14 (46%); however, as previously noted, it could not
be determined it the material retrieved by coring at this site was sediment or original
substrate. Bulk density was highly variable across the reservoir (Table 5).
Sediment core LOVE-4, located near the lower end of the reservoir, was sliced into 5cm sequential sections in the field and bagged in whirl-paks. Samples were sent to the
Kansas State University Soil Testing Laboratory (Manhattan, KS) for analysis of total
nitrogen (total N) and total phosphorus (total P) to create a chronosequence of nutrient
levels in the sediment column (Each sample provided insufficient material for a
texture/particle size analysis). Total nitrogen (ppm) averages over 1000 ppm for the
entire core, and increases from less than 1500 ppm to over 2000 ppm in the upper 30
cm of the core. Highest total nitrogen was in the topmost sample, at the sediment-water
interface (Figure 13). Total phosphorus (ppm): Patterns of total P in the sediment
column did not vary substantially, averaging ~500-600 ppm (Figure 14).
20
21
!
.
LOVE-11
!
.
LOVE-10
Figure 9. Sediment coring sites, Lovewell Reservoir.
!
.
LOVE-13
!
.
LOVE-12
!
.
LOVE-9
!
.
LOVE-7
!
.
!
.
LOVE-5
LOVE-8
!
.
0
LOVE-14
!
.
LOVE-6
0.25
0.5
!
.
LOVE-4
!
.
!
.
LOVE-2
!
.
1
Miles
Ü
LOVE-3
LOVE-1
22
0
!
.
!
.
0
!
.
22
!
.
50
!
.
20
5
!
.
Figure 10. Sediment thickness in centimeters at coring sites, Lovewell Reservoir.
Code of 9999 indicates indeterminate thickness /unable to determine.
!
.
0
5
!
.
!
.
0
9999
!
.
20
0.25
0.5
!
.
110
!
.
85
!
.
205
1
Miles
Ü
!
.
60
Table 5
Lovewell Reservoir Sediment Coring Site Data
UTMX
UTMY
Sediment
Thickness
(cm)
LOVE-1
582472
4417168
85
0.63
4
58
38
LOVE-2
582927
4416551
60
0.61
6
46
48
LOVE-3
582794
4415762
205
0.51
4
38
58
Code
Mean
Bulk Density
(g/cm3)
Sand
%
Silt
%
Clay
%
Sampled sliced in 5-cm increments for nutrient sequence
analysis
LOVE-4
582088
4415687
110
LOVE-5
580587
4415982
5
n/d
16
42
42
LOVE-6
581257
4416354
20
0.49
12
42
46
LOVE-7
580044
4416453
50
0.57
4
40
56
LOVE-8
580281
4417319
20
0.64
12
46
42
LOVE-9
579207
4417567
22
0.74
12
56
32
LOVE-10
578699
4416901
0
n/d
n/d
n/d
n/d
LOVE-11
578085
4417409
0
n/d
n/d
n/d
n/d
LOVE-12
577601
4417638
5
n/d
16
60
24
LOVE-13
576800
4417381
0
n/d
n/d
n/d
n/d
LOVE-14
581294
4415702
9999
n/d
46
44
10
Note:
n/d = Sample or bulk density not collected due to insufficient core size.
“9999” indicates indeterminate sediment thickness.
UTM coordinates datum NAD83, Zone 14N, units meters.
23
Lovewell Reservoir
2012 Sediment Particle Size Analysis
100%
90%
80%
70%
60%
CLAY
50%
SILT
40%
SAND
30%
20%
10%
LO
VE
-1
LO
VE
-2
LO
VE
-3
LO
VE
-4
LO
VE
-5
LO
VE
-6
LO
VE
-7
LO
VE
-8
LO
VE
L O -9
VE
-1
0
LO
VE
-1
1
LO
VE
-1
2
LO
VE
-1
3
LO
VE
-1
4
0%
Sample Site
Figure 11. Sediment particle size analysis.
24
25
!
.
!
.
LOVE-11
!
.
LOVE-10
!
.
!
.
!
.
!
.
Figure 12. Particle size distributions at sediment coring sites, Lovewell Reservoir.
Clay
Silt
Sand
Particle Size
Distribution
!
.
LOVE-13
!
.
!
.
0
0.25
0.5
!
.
LOVE-4
!
.
!
.
1
Miles
Ü
!
.
Total N
LOVE-4-110
LOVE-4-105
LOVE-4-100
LOVE-4-95
LOVE-4-90
LOVE-4-85
LOVE-4-80
LOVE-4-75
LOVE-4-70
LOVE-4-65
LOVE-4-60
LOVE-4-55
LOVE-4-50
LOVE-4-45
LOVE-4-40
LOVE-4-35
LOVE-4-30
LOVE-4-25
LOVE-4-20
LOVE-4-15
LOVE-4-10
LOVE-4-5
0
500
1000
1500
2000
Total N (ppm)
Figure 13. Total nitrogen (ppm) from sediment chronosequence of core LOVE-4.
26
2500
Total P
LOVE-4-110
LOVE-4-105
LOVE-4-100
LOVE-4-95
LOVE-4-90
LOVE-4-85
LOVE-4-80
LOVE-4-75
LOVE-4-70
LOVE-4-65
LOVE-4-60
LOVE-4-55
LOVE-4-50
LOVE-4-45
LOVE-4-40
LOVE-4-35
LOVE-4-30
LOVE-4-25
LOVE-4-20
LOVE-4-15
LOVE-4-10
LOVE-4-5
0
100
200
300
400
500
600
Total P (ppm)
Figure 14. Total phosphorus (ppm) from sediment chronosequence of core LOVE-4.
27
700
800