Tuesday, January 3, 2017

Lake Como Restoration

Post contributed by Liam Krause and Dennis Walsh, Conservation Corps of Minnesota:

Who doesn’t enjoy a refreshing jaunt around Como Lake?  With almost two miles of walking and biking paths, paddleboats available for rent, and refreshments waiting at Como Dockside, there is something to do for everyone.  For over 100 years, Como Lake’s proximity to Saint Paul has been a welcome respite for from urban life for residents, but Como's proximity to the city is beginning to take a toll on the health of our lake. 

The Problem

Have you ever noticed the greenish hue on Como Lake during the summer months? That coloration is indicative of a process called nutrient loading. This phenomenon occurs when too much of one or more nutrients makes its way into a body of water. This can happen when runoff draws sediment off the roads or fertilizers off our lawns as it drains into a lake, pond, or river. When a body of water takes in excessive nutrients, it promotes disproportionate algae growth. The algae soon dies, leaving decaying organic matter. The decomposition process consumes dissolved oxygen in the water, oxygen that other living things in the lake depend on. This could potentially create a "dead zone." This is happening to Como Lake. For a more detailed outline of contributing factors and findings specific to Como Lake, visit the report published by the Capitol Region Watershed District (CRWD).

What We've Done

Huge brush pile of invasive species created by volunteers.
With the help of a CRWD cost-share grant program, and the efforts of the Conservation Corps of Minnesota and Iowa, the City of Saint Paul has taken big steps in reducing the sedimentation and runoff going directly into our lake. The North Lake Como Restoration project has targeted 4.25 acres of disturbed land in order to enhance and restore important oak savanna and woodland habitats. When completed, the changes to the target areas will help recharge groundwater, improve the water quality of the lake, and provide a diverse environment for wildlife.

First, the target areas were swept for invasive species such as buckthorn, black locust, mulberry, and honeysuckle. These species disrupt natural biodiversity and choke out herbaceous ground cover, which can result in increased erosion. Thanks to the hard work of volunteers, all of the cut material was hauled offsite. The site was then prepared for seeding. Along East Como Lake Drive, all of the leaf litter was removed in preparation for a process called hydromulching. Hydromulching is the application of seed and mulch to reestablish vegetation, often used to control erosion and retain soil moisture. A cover crop, and a native grass seed mix was broadcast throughout the project area and erosion control materials have been laid. With any luck, Saint Paul residents will start to see healthy shoots of little bluestem, canada wild rye, and indian grass popping up as they walk around Como Lake this spring.

East Como Lake Drive before invasive species removal and hydromulching (left) and after (right).

What You Can Do

Nutrient loading is the effect of too much moving from our lawns to our lakes. In order to counteract the process, it will take the sustained combined effort of everyone in the area to restore Como Lake to a healthy state. Some of the things you can do to help are limiting the use of lawn fertilizer, install buffer strips or rain gardens, and keep your eye out for volunteer events with the City of Saint Paul. If you are interested in making greater changes to combat the effects of nutrient loading, the Minnesota Pollution Control Agency has a list of steps you can take. Together we can protect this popular Saint Paul destination.