confluence at the confluence chatfield watershed authority september 22, 2014
TRANSCRIPT
2014 Overview of Chatfield Watershed• Where we’ve been
• What the Future looks like
• Partnerships – It’s all about “Making Connections”
Authority’s Goals Promote Watershed Health…
• Meet water quality requirements and protect beneficial uses.
• Serves as the designated 208 water quality management or planning agency for water quality
• Implement projects or monitor and quantify benefits of watershed projects constructed by others.
• Measure and document water quality improvements.
• Work with watershed stakeholders on common water quality goals.
Chatfield Watershed
Size: Approximately 400 mi2
Location: Douglas, Jefferson, and El Paso counties
Drainages: South Platte, Plum Creek, Deer Creek, and Massey Draw
Through the Years - Chatfield ReservoirWater Quality Requirements• Regulation 73 is established in 1984 by WQCC
– 27 ug/L established as the in-lake Phosphorus standard– Translated into permits as 0.2 mg/L Phosphorus limit
• 1993 – 59,000 pounds TMAL – 17 ug/L set as Chlorophyll-a GOAL– POTW permit limits to 1.0 mg/L 30 day average with annual
pounds• Housekeeping changes in between• 2009
– TMAL revised to 19,600 pounds/year – nearly 40,000 lbs. reduction
• What’s next?? – POTW allocations??
Current Water Quality Standards
• In-lake TP standard (July – Sep) - 30 ug/L; assessment threshold – 35 ug/L, 1-in-5 year exceedance frequency.
• In-lake chlorophyll-a standard (July – Sep) - 10 ug/L; assessment threshold – 11.2 ug/L, 1-in-5 year exceedance frequency.
• Phosphorus TMAL of 19,600 pounds.
• In-lake swim beach E. coli standard of bacteria <126/100mL.
CWA Activities till Now
• Participation from MS4s and POTWs and other affected entities
• Funding from voluntary annual contributions• Some watershed studies• 2013-2014 Watershed Planning effort
• Monitor, monitor, monitor
Amateur Limnology
• Building a reservoir and keeping water in it leads to eutrophication
• One can’t control nature• Nutrients happen and no matter how low POTWs
treat for them, nutrients will still happen in reservoirs – i.e., non-point pollution
• Thermoclines, turnover and internal loading happens
• Have we been set up to fail by the latest control regulation modification?? Probably
• What recourse?• Better modelling of the watershed and reservoir
2014 Authority Priorities• Complete Watershed Plan.• Beginning a conversation on funding strategies to
support the monitoring, studies, and projects identified in the Watershed Plan.
• Partnerships• Continuing collaborative efforts with the Chatfield
Reallocation Water Providers on data collection, modeling and water quality improvement projects.
• Develop other partnerships – Other watershed groups – BMW– Agricultural interests– Upper SP Watershed