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 mi2

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 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

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