Unfortunately, stormwater runoff from the lake’s urban surroundings has hurt its water quality. In addition to nutrient pollution, sediment and high algae growth in the summer have changed Como Lake’s natural balance. Historically, sediment from construction, roads and general erosion has been a significant water quality challenge for the lake, reducing overall lake volume and decreasing habitat value for the lake’s fish populations. However, Como Lake’s greatest water quality problem is excessive phosphorus, which has caused annual algal blooms and overgrowth that has further damaged the integrity of the lake.Visit Map
Background & Updates
District residents need no introduction to Como Lake and its parkland, a popular spot for recreation in the City of Saint Paul. Como Lake draws more than 4.3 million visitors each year for outdoor activities, including Como Regional Park and Golf Course and the lake’s surrounding attractions. The 70 acre lake drains more than 1,711 acres of land in Saint Paul, Roseville, and Falcon Heights.
With a maximum depth of 15.5 feet, Como Lake is a shallow body of water. The shallow depth of the lake, coupled with large nutrient inputs from upland areas, has had a significant impact on Como Lake water quality. In fact, CRWD began when a group of residents raised concerns about the water quality in Como Lake. Accordingly, the District has placed a high priority on improving Como Lake, as it is one of the most recognizable and well-loved water resources.
Fall 2021 Update – Native Aquatic Plant Nurseries
CRWD and the Minnesota Department of Natural Resources (DNR) are working to create a more diverse aquatic plant community in Como Lake by transplanting a variety of native plant species from a nearby lake.
If you visit Como Lake this fall look for fenced areas in the lake. These fenced-in areas serve as nurseries for the transplanted aquatic plants and protect them so they can take root, grow, and eventually produce more plants. CRWD will be closely monitoring the nurseries to see how the transplanted plants establish in their new environment.
Aquatic plants are an important part of a lake’s ecosystem because they provide food and shelter for wildlife such as ducks, turtles, fish, and bugs. Como Lake’s native aquatic plant community has declined over the years due to poor water quality conditions and the takeover of an invasive aquatic plant called curly-leaf pondweed. CRWD has been working to reduce curly-leaf pondweed in the lake to allow for native plants to return as part of the ongoing effort to improve Como Lake.
Landmark Improvements in Como Lake's Water Quality!
In spring 2020, CRWD carried out two treatments in the lake to improve water quality. Following the treatments, Como Lake nearly met the state standard for phosphorous for the first time on record!
Como Lake Health
Stormwater runoff from the lake’s urban surroundings has hurt its water quality. In addition to nutrient pollution, sediment and high algae growth in the summer have changed Como Lake’s natural balance. Historically, sediment from construction, roads and general erosion has been a significant water quality challenge for the lake, reducing overall lake volume and decreasing habitat value for the lake’s fish populations. However, Como Lake’s greatest water quality problem is excessive phosphorus, which has caused annual algal blooms and overgrowth that has further damaged the integrity of the lake.
The Como Lake watershed has 13 major subwatersheds within its boundaries. A subwatershed is a localized drainage area within a greater watershed. Understanding the characteristics of each Como Lake subwatershed is important for managing runoff to Como Lake because each behave differently depending on their land use, topography, soil types, and drainage pathways to the lake. An important characteristic of the Como subwatersheds is that the drainage pathways are conveyed primarily via storm sewers—the Como Lake watershed has a dense storm sewer network that effectively transports runoff to the lake. Because of this, the landscape of each subwatershed is directly connected to the lake. There are 22 stormwater outfalls that directly drain into Como Lake. A large portion of the watershed consists of impervious surfaces (40%), which includes roads, parking lots, driveways, sidewalks, and rooftops—any type of hard surface that water cannot infiltrate through. As rain falls on these impervious surfaces, water flows across and becomes “runoff”. The stormwater runoff picks up pollutants (e.g. nutrients, road salt, heavy metals) on the impervious surfaces and quickly enters stormwater pipes which discharge into local water bodies like Como Lake. Learn more about the Como Lake Watershed
Como Lake Management Plan
CRWD is committed to improving water quality in Como Lake. In 2002, CRWD created a strategic plan (view 2002 Como Lake Strategic Management Plan) that guided the District and its partners to address Como Lake water quality priorities. In 2017, CRWD conducted the Como Lake Water Quality Drivers Analysis Study to better understand what is causing the lake’s poor water quality. Based on the results of this study and ongoing monitoring, the District created a revised Como Lake Management Plan (CLMP) in 2019 that also includes input from residents and community partners. The revised plan builds on the past two decades of work around the lake with a specific focus on management within the lake. The goals of the CLMP are:
- Goal 1: Como Lake will be managed as an ecologically healthy, shallow lake.
- Goal 2: Maintain healthy shoreline areas that can support a variety of wildlife and contribute to the ecological health of Como Lake.
- Goal 3: Maintain a variety of year-round recreational opportunities that are appropriate for a shallow urban lake
- Goal 4: Achieve strong sustained community engagement and stewardship to improve and protect Como Lake
- Goal 5: Utilize the best science, partnerships, and resources to ensure successful implementation of the CLMP over the life of the plan (20 years).
The life of the revised plan is defined as 20 years (2019-2039) to allow enough time for Como Lake to respond to in-lake and watershed management actions and achieve ecological balance. The CLMP is an adaptive management plan and will be updated every few years as short-term actions are implemented and evaluated.View Como Lake Management Plan