The Urban Lake Renewal Project will result in collaborative projects and programs with municipal and community partners that improve water quality in two of the state’s most visited urban lakes, Como Lake in Saint Paul and Lake McCarrons in Roseville. An estimated 4.48 million people visit Como Lake Regional Park each year. The lake is a highly valued, iconic natural resource in the Twin Cities metropolitan area. Lake McCarrons spans nearly 75-acres and hosts swimming, boating, and fishing. A Ramsey County Park provides public access and is the only designated public swimming beach in CRWD. The benefits of this project are expected to improve water quality and recreation opportunities for millions of Minnesota residents.
This project aims to improve water quality in Como Lake, which is impaired for phosphorous, and protect Lake McCarrons which has demonstrated a decline in water quality in recent years but is not designated as impaired. Work will begin in the fall of 2016.
To meet state standards, Como will require a 60% reduction in phosphorous from stormwater runoff and a 97% reduction in phosphorous being recycled inside of the lake. Excess phosphorous fuels algae growth. Less phosphorous means clearer water.
Although Lake McCarrons is not impaired, 2014 monitoring data showed an increase in phosphorus and algae (chlorophyll-a) concentrations. In 2004, CRWD treated the lake with aluminum sulfate (alum). Alum binds with phosphorous, making it unavailable for algae to consume. The expected lifespan of an alum treatment is 8-20 years. Reductions in phosphorus inputs are needed to protect water quality.
Project Scope of Work
Meeting water quality goals for each lake will require a combination of stormwater improvement projects to collect and treat runoff draining to the lakes, in-lake management strategies and a Clean Streets Initiative.
Solution 1: Large Scale Best Management Practice (BMP) Implementation
CRWD will further evaluate potential project locations in each subwatershed and collaborate with municipal and community partners to construct large scale BMPs.
Solution 2: The Clean Streets Initiative
CRWD staff work with residents, municipal, and community partners to prevent, remove, and treat polluted runoff before it enters storm drains, flows into nearby Como and Lake McCarrons, ultimately reaching the Mississippi River. Initiatives may include:
- Boulevard rain gardens
- Expansion of the residential Adopt-a-Drain program
- Expansion of neighborhood leaf cleanup events
- Expanded and targeted street sweeping
CRWD estimates the Urban Lake Renewal Project will achieve over 25% of the watershed phosphorus load reduction (100 lbs. reduction) for Como Lake. It will also result in treatment of a significant portion of the Lake McCarrons subwatershed, which will increase the lifespan of in-lake management strategies.
CRWD received a $1.76 million grant award from the MN Board of Water and Soil Resources (BWSR) to improve water quality in Como Lake and Lake McCarrons. The funds, made available through the Clean Water, Land and Legacy Amendment, were approved by BWSR as part of the Targeted Watershed Program. Additional project funding will be provided by CRWD totaling $440,000. Potential project partners include Ramsey County and the Cities of Saint Paul, Roseville, and Falcon Heights.