Confluence at the Confluence Chatfield Watershed Authority September 22, 2014

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 mi 2 Location: Douglas, Jefferson, and El Paso counties Drainages: South Platte, Plum Creek, Deer Creek, and Massey Draw

Chatfield State Park – Most Highly Used State Park in Colorado

Through the Years - Chatfield Reservoir Water 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 Watershed Planning effort Monitor, monitor, monitor

Total Phosphorus Compliance In Chatfield Reservoir

Chlorophyll-a Compliance in Chatfield Reservoir

2013 Another Dry Year in the Chatfield Watershed

Chatfield Below the Phosphorus TMAL

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

Chatfield Watershed Planning Effort included Nine Public Stakeholder Meetings in 2013

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

Questions? Photograph by Thad Roan