St. Johns County s Approach to Merging Water Quality and Supply Challenges

Transcription

1 St. Johns County s Approach to Merging Water Quality and Supply Challenges 1

2 Introductions Greg Caldwell, MPA Capital Improvement Program Manager, St. Johns County Engineering Mark Nelson, PE Vice President Jones Edmunds & Associates

3 St. Johns County St. Augustine World Golf Village Ponte Pedra TPC Sawgrass Agriculture (TCAA) 35-40% wetlands and water FSA Program Excellence Award

4 St. Johns County Growth ~217,000 people Population doubled in 20 years County maintained roads up >50% in 10 years building permits per year 10

5 St. Johns County Challenges Stormwater Quantity Quality Groundwater Quantity Quality Revenue Declining/flat revenues Increasing infrastructure No dedicated stormwater funding source

6 County Strategy Water Quantity Stormwater Modeling Existing initiative Leverage County s existing investments Improve County s understanding of hydrology, hydraulics, floodplains, etc. Improve understanding of flood risks Lower County s liabilities Foundation for water quality modeling

7 County Strategy Water Quality Existing BMAP, Adopted TMDLs and Impairments Cost-effectively improve surface water quality Assess and manage liabilities Minimize County s costs Identify sustainable funding source Trust but verify 11

8 County Strategy Water Quality Monitoring Improve understanding of water bodies and issues Add clarity to FDEP monitoring data Success in delisting and improving FDEP s understanding Reduction of >100,000 lbs/yr in nutrient requirements County WQ Monitoring 12

9 Water Quality Program Implementation Capital Improvement Projects Current CIPs: Baffle Boxes Masters Tract RST Deep Creek West RST Modifications Potential Capital Project(s) Stormwater Harvesting Parker Canal RST Retrofits Stormwater Harvesting to Tater Farms

10 Masters Tract Background SJRWMD Property Purchase St. Johns County Preliminary Evaluation Property Purchased from SJRWMD Design Grants Construction - Phase 1 AWS Design Construction - Phase 2

11 Masters Tract Design Overview Wetlands 50 acres forested wetland creation 15 credits 1,300 1,700 #/yr TN Canal 4 / HDD 300 acre watershed # /yr TN 5 Credits Wet Pond 30 acres 40 day res. time 2,400 3,500 #/yr TN Intake Pump Station 1 cfs baseflow and 2-9 cfs stormflow submersible pumps Canal 5 1,200 acre watershed 5,600 8,200 # /yr TN captured, 1-4 mg/l TN, cfs Stormwater Harvesting Offsetting ~1 MGD UFA 1,300 1,900 #/yr of TN

12 Masters Tract Construction Forebay / Canal 5 Intake Pump Station Pond Outfall Splitter Box 10

13 Masters Tract Stormwater Harvesting Initially designed as a pilot Considered interconnect w/ Deep Creek West Cost-effective alternative for nutrients alone Partnered w/ sod grower Designed SJRWMD Cost-Share Bid/Award Construction - Phase 2

14 Masters Tract Stormwater Harvesting

15 Masters Tract Stormwater Harvesting ~10,000 of 12 PVC 850 GPM submersible pump ~50% of capital costs grant funded # TN/yr reduction Offset ~1 MGD of UFA water use Irrigating 170 acres of sod

16 Masters Tract Challenges Design Flows (Canal 5 & 4) Water table Wetlands Easements Inline/Offline Construction Agriculture Community Lowest cost alternative Credits Food Safety Modernization Act Agreement / Contract CUP Existing Masters CUP Growers CUP

17 Masters Tract Funding $4.8 million construction $1.9 million Phase 1 $2.9 million Phase 2 Funding Sources $2.6 million St. Johns River legislative appropriation $796 k FDEP/EPA 319 Grant $371 k SJRWMD Cost- Share $203k County Tree Funds

18 Masters Tract Summary 5,000 7,000 #/yr of TN removal Offset up to 1 MGD UFA Retires ~1 MGD UFA Generates 20 FGU/UMAM credits offsetting $2.5 million in mitigation costs for CIPs > 80% funding from grants and other sources

19 Deep Creek West Improvements Background 15-acre pond 38-acre wetland 1200 acre watershed Owned by SJRWMD O & M by County Credits Ongoing Efforts Construction Grant funded by SJRWMD Increased load reductions by 50% More efficient pump operations Increase wetland performance Master Tract

20 Deep Creek East Hybrid Wetland Treatment Technology (FDACS) Currently owned by SJRWMD Funded by FDACs Load reduction credits to FDACS/Agriculture

21 Parker Canal Regional Stormwater Treatment Elkton Drainage District (County) 3,700 acre basin Baseflow 10 cfs, up to ~1,000 cfs Total Nitrogen outflows ~30,000-40,000 #/yr Alternatives Analysis Co-funded by SJRWMD Multiple options evaluated Recommended - 19 acre pond w/ a 8 cfs pumped inflow Load reduction of ~13,000 # TN/yr Provide/offset 4 MGD

22 Integrated Water Resources Plan Utilities Department Jones Edmunds & CDM Alternative Water Supply Stormwater harvesting sources for supplemental reuse or offsets Masters Tract RST Fox Creek RST Parker Canal RST

23 Present/Future Planning WQ CIPs Engage Stakeholders Developers Agriculture Build on successes Active participant Monitoring Planning Sustainable Partnerships Grants Challenges Regulatory Funding