Lake Tohopekaliga Nutrient Reduction Plan

Transcription

Lake Tohopekaliga Nutrient Reduction Plan
Lake Tohopekaliga Nutrient Reduction Plan
Danielle Honour, P.E., D.WRE
Principal
Kimberly Lawrence
Stormwater Program Manager
Florida Stormwater Association 2011 Winter Conference
December 7, 2011
Lake Tohopekaliga (Toho) Background
• Upper Kissimmee River Basin
• 34 square miles in size
• Watershed area approximately
• 473 square miles
– 17 square miles
– Closed basins
• Class 3 fresh water lake
• Heavily used for fishing, hunting, boating, bird watching, and sightseeing
Lake Tohopekaliga Background
Overview of Lake Toho Impairment
• Placed on Verified List by FDEP in November 2010
• Lake Toho initially impaired for nutrients [(i.e., increasing trend in Trophic State Index (TSI)]
• Assessment Category 5 ‐ water quality standards are not attained and a Total Maximum Daily Load (TMDL) is required
• Osceola County and the City of
Kissimmee disagreed with
the initial listing
• Performed independent analysis that showed no impairment
Lake Tohopekaliga Background
Overview of Lake Toho Impairment (cont.)
• FDEP re‐considered modifying the cause of impairment for the lake as an imbalance of flora and fauna, which is included under the narrative nutrient criteria in Chapter 62‐303, FAC
• FDEP willing to change assessment category to 4e if a Nutrient Reduction Plan (NRP) is prepared
• Final listing delayed until December 2011
“TSIs and annual mean chlorophyll a values shall be the primary means for
assessing whether a water should be assessed further for nutrient impairment.
Other information indicating an imbalance in flora or fauna due to nutrient
enrichment, including, but not limited to, algal blooms, excessive macrophyte
growth, decrease in the distribution (either in density or areal coverage) of
seagrasses or other submerged aquatic vegetation, changes in algal species
richness, and excessive diel oxygen swings, shall also be considered.”
Lake Tohopekaliga Background
Lake Management History
• Lake Toho has been highly managed since the 1960s
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Water level stabilization (1960s)
Sewage treatment plant effluent discharges (1940s to 1980s)
Major drawdowns to improve habitat (1969, 1979, 1987, 2004)
Introduction of Hydrilla spp. into the lake (1980s)
• Impact of management activities on water quality not fully understood
• FDEP agrees that more research and a better understanding of lake dynamics is needed before appropriate water quality targets can be set for the lake
• Local MS4 permit holders held accountable for impairment
Lake Tohopekaliga Background
Competing Interests Make Water Quality Improvements a Challenge
• Alteration of natural hydrology and lake level stabilization – Flood control purposes (Corps, SFWMD)
– Fish habitat improvement (i.e., drawdowns) (FWCC)
– Snail kite nesting
• Aquatic plant management (FWCC)
– Herbicide treatments can contribute to buildup of organic
sediments and storage of nutrients in sediments – Snail kite nesting and foraging habitat
Lake Tohopekaliga Background
What is a Nutrient Reduction Plan?
• Hybrid of a Basin Management Action Plan (BMAP) and a Reasonable Assurance Document (RAD)
• Key differences:
No water quality “targets” are set
Loads are not allocated
Not a restoration plan Monitoring plan and research priorities
will align specifically to the goals and objectives identified by the stakeholders to determine true future targets
– Not a long‐term solution: stepping stone
– Plan is not formally “adopted” –
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Nutrient Reduction Plan
Who are the Participating Stakeholders?
NRP Funding Plan Partners
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City of Kissimmee
City of Orlando
City of St. Cloud
Florida Department of Transportation (FDOT)
Osceola County
Technical Resources and Plan Support
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Nutrient Reduction Plan
FDEP
Florida Farm Bureau
Florida Department of Agriculture and Consumer Services (FDACS)
Florida Fish & Wildlife Conservation Commission (FWCC)
South Florida Water Management District (SFWMD)
Orange County
Reedy Creek Improvement District
Purpose of the Nutrient Reduction Plan
• Document local efforts that achieve nutrient reductions (TN and TP)
• Provide additional time to assess the complex relationships within the lake
• Focuses on reducing nutrient loads that can be achieved through management activities, capital improvement projects, non‐structural best management practices, and/or research activities • Can only control what’s in your own “backyard”
Nutrient Reduction Plan
Benefits of Nutrient Reduction Plan
• Eliminates short‐term need for TMDL
• May eliminate the long‐term need for TMDL
• “Control your own destiny”
– Allows flexibility
• FDEP provides support where needed
• Work closely with FDEP so that NRP is accepted
• Begins reduction activities quickly
• Potential long‐term cost savings
Small investment helps focus where efforts should
be vs. spending millions on questionable targets
Nutrient Reduction Plan
Benefits of Nutrient Reduction Plan (cont.)
• FDEP moves Lake Toho to Category 4e (restoration activities)
• Avoids additional permit requirements under a TMDL
• Allows for more time for lake dynamics to be understood so that appropriate water quality targets can be set in the future
• May discover that there is no “causative pollutant” for the excessive macrophyte
impairment: Category 4d • Enhancement of public relations
• Prepare for downstream TMDLs Nutrient Reduction Plan
Nutrient Reduction Plan Approach
• Estimate existing annual stormwater‐related anthropogenic land‐based pollutant loads generated from land surface (i.e., loads that stakeholders can control)
• Define existing loads by jurisdiction
• Evaluate load reduction associated with planned projects/activities
• NRP modeling will not be used for the following:
– Setting water quality targets
– Determining load allocations
Approach
Modeling Approach
• Applied HSPF model used for Kissimmee River Basin TMDL modeling
• Used HSPF output in conjunction with GIS layers to estimate land‐based loading for all jurisdictional entities (including agriculture)
• Apply attenuation factors to account for natural assimilation processes
• Calculated baseline load (untreated load)
• Calculated existing treated load (accounting for BMPs)
• Year 2008 as the starting point of analysis
Approach
Modeling Approach (cont.)
Loading Rates
Soil TP
TN
Type (lb/ac/yr) (lb/ac/yr)
A
1.96
14.3
B
2.01
14.7
Commercial/Industrial
C
2.04
15.0
D
2.08
15.3
A
0.23
1.7
Cropland/
B
0.95
6.8
Improved Pasture
C
1.43
10.3
D
2.11
15.4
A
1.26
9.2
High Density B
1.40
10.4
Residential
C
1.48
11.0
D
1.57
11.8
A
0.33
2.5
Low Density B
0.60
4.6
Residential
C
0.77
5.9
D
0.95
7.3
A
0.68
5.0
Medium Density B
0.91
6.8
Residential
C
1.04
7.9
D
1.20
9.0
A
0.02
0.5
B
0.12
1.7
Forest/
Rangeland
C
0.18
2.6
D
0.29
3.6
A
0.06
0.7
B
0.32
2.9
Unimproved Pasture
C
0.49
4.4
D
0.72
6.3
A
‐‐‐
‐‐‐
B
‐‐‐
‐‐‐
Wetland
C
‐‐‐
‐‐‐
D
0.09
1.4
Land Use Category
Land Use
Soils
Subbasins
Existing BMPs
Nutrient Reduction Plan
Baseline Pollutant Load Results
Developed Area (Acres)
TN Anthropogenic Load (lbs/yr)
TN Natural
Load (lbs/yr)
TP TP TN Total Anthropogenic Natural
Load Load Load (lbs/yr)
(lbs/year)
(lbs/year)
TP Total Load (lbs/yr)
80,033
22,968
180,399
83,266
263,665
21,054
4,791
25,845
11,731
3,533
8,198
88,912
5,202
94,113
11,867
379
12,246
City of St. Cloud
8,582
2,146
6,436
56,658
3,451
60,109
6,740
251
6,991
Orange County
83,500
41,755
41,745
313,648
51,436
365,084
31,878
2,653
34,531
City of Orlando
34,302
11,856
22,446
130,501
13,281
143,782
12,792
601
13,393
FDOT
2,501
292
2,209
26,222
463
26,686
3,183
36
3,219
Agriculture
39,310
‐‐‐
‐‐‐‐
‐‐‐
‐‐‐
208,412
‐‐‐
‐‐‐
19,505
Other
19,956
9,028
10,928
92,603
8,692
101,295
5,966
228
6,194
148,643
154,240
888,943
165,791
1,263,146
93,480
8,939
121,924
Jurisdiction/ Area
Area Natural (Acres) Area (Acres)
Osceola County
103,001
City of Kissimmee
Totals: 302,883
Results
Existing Treated TN Load Results
Jurisdictional Area
(ac)
TN
Baseline Anthropogenic Load
(lbs/yr)
TN Existing Anthropogenic Load
(lbs/yr)
TN
Anthropogenic
Load Reduction (%)
Osceola County
103,001
180,399
140,698
22.0%
82,198
222,896
City of Kissimmee
11,731
88,912
70,175
21.1%
4,834
75,009
City of St. Cloud
8,582
56,658
42,152
25.6%
3,292
45,444
City of Orlando
34,302
130,501
86,470
33.7%
11,393
97,863
FDOT
2,501
26,222
20,848
20.5%
389
21,237
160,117
482,692
360,343
25.3%
102,106
462,449
Jurisdiction/ Area
Totals:
Results
TN Natural
Treated Load TN Total Existing Load (lbs/yr)
(lbs/yr)
Existing Treated TP Load Results
Jurisdictional Area
(ac)
TP
Baseline Anthropogenic Load
(lbs/yr)
TP Existing Anthropogenic Load
(lbs/yr)
TP
Anthropogenic
Load Reduction (%)
Osceola County
103,001
21,054
13,253
37.1%
4,674
17,927
City of Kissimmee
11,731
11,867
7,357
38.0%
327
7,684
City of St. Cloud
8,582
6,740
3,681
45.4%
230
3,911
City of Orlando
34,302
12,792
6,484
47.1%
435
6,919
FDOT
2,501
3,183
2,227
30.0%
27
2,254
160,117
55,636
33,002
40.6%
5,693
38,695
Jurisdiction/ Area
Totals:
Results
TP Natural
Treated Load TP Total Existing Load (lbs/yr)
(lbs/yr)
Management Actions to Reduce Nutrient Loading
• Stakeholders provided information on projects and programs in place since 2009 or will be implemented to reduce external nutrient loads to Lake Toho over the next five years
– All projects and programs required to address nutrient loads (specifically TN and TP) to receive credit
– Future management actions were given credit for the portion of the load reduction that was over and above any permit requirements
Stakeholders are committing to
reducing external nutrient loads
to Lake Toho
Management Actions
Management Actions to Reduce Nutrient Loading (cont.)
Project Number
Project Name
Project Type
Treatment Acres
2,300
Project Cost
End Date
Status
Unknown
2009
Completed
TN Reduction (lbs/yr)
TP Reduction (lbs/yr)
Osceola County
OSC‐11
Stewart Street Regional Pond Retrofit
Wet detention pond
OSC‐12
East Lake Reserve Reuse
Stormwater reuse
3.7
Unknown
12/2028
OSC‐13
Bass Road Landfill Reuse
Stormwater reuse
0.9
Unknown
OSC‐14
Neptune Road Reuse Stormwater reuse
3.0
OSC‐15
Waterside Vista Reuse
Stormwater reuse
OSC‐16
Bellalago & Isles of Bellalago Reuse
2,667.0
381.3
Ongoing
255.9
5.8
04/2031
Planned and Funded
537.1
40.2
$640,690
09/2027
Ongoing
849.0
62.0
0.3
Unknown
02/2030
Ongoing
29.0
0.7
Stormwater reuse
327
Unknown
05/2031
Ongoing
3,807.5
277.6
OSC‐17
Poinciana Commerce Stormwater reuse
Center Reuse
1.3
Unknown
06/2028
Ongoing
33.6
2.8
OSC‐18
Kissimmee Bay Reuse
Stormwater reuse
130.0
Unknown
10/2030
Ongoing
588.9
13.1
OSC‐19
Remington Reuse
Stormwater reuse
139.0
Unknown
11/2015
Ongoing
382.6
15.1
OSC‐20
Eagle Lake Reuse
Stormwater reuse
17.3
Unknown
07/2023
Ongoing
1,204.6
84.6
OSC‐21
La Quinta Inn Reuse
Stormwater reuse
2.8
Unknown
10/2022
Ongoing
90.8
7.0
OSC‐22
Street Sweeping
Street Sweeping
N/A
Unknown
Ongoing
Ongoing
226.8
151.2
OSC‐23
Education
Education
N/A
Unknown
Ongoing
Ongoing
8,441.9
795.2
Management Actions
Project Load Reduction Summary
Jurisdiction
Project TN Load Reduction (lbs/yr)
Project TP Load Reduction (lbs/yr)
City of Kissimmee
3,070
1,204
City of St. Cloud
2,529
221
Osceola County
19,154
1,844
City of Orlando
7,986
2,505
FDOT
1,380
416
225
97
34,344
6,287
Orange County
Totals:
Management Actions
Water Quality Monitoring Plan
• Objective: Identify major inputs to Lake Toho and East Lake Toho to calculate the loading to the impaired waterbodies and to identify areas of high nutrients in the watershed
• Stakeholders worked to identify stations within watershed
Tributaries Sampling
In‐Lake Sampling (SFWMD)
Core Parameters
Total phosphorus as P
Core Parameters
Supplemental Parameters
Total phosphorus as P
Total suspended solids (TSS)/turbidity
Orthophosphate as P
Nitrate/nitrite as N
Chloride
Total Kjeldahl nitrogen (TKN)
Total Kjeldahl nitrogen (TKN) as N
True color/total organic carbon (TOC)
Dissolved oxygen (DO)
Orthophosphate as P
pH
Alkalinity
Temperature
Conductivity
Nitrate/nitrite as N
Ammonium
Nitrogen dioxide
Chlorophyll
Alkalinity
Turbidity
Chloride
Color
TSS
Water Quality Monitoring Plan
Next Steps: Acceptance and Implementation
• FDEP Review of NRP (December 2011)
• Change assessment category to 4e by December 2011
• Establish research priorities
– Literature search on linkage between submerged aquatic vegetation (hydrilla) and nutrients is underway (University of Florida)
• Implement water quality monitoring program
• Track implementation
– Periodic stakeholder meetings and coordination
Next Steps
Questions and Discussion
Questions