Crystal Lake Water Quality: 

Crystal Lake has been on the Minnesota Impaired Waters list since 2002 due to the lake’s high-level of nutrients. Excessive nutrients, such as phosphorus, can negatively impact the health of the lake by promoting nuisance algae growth. Throughout the last four years, the City of Robbinsdale and the Shingle Creek Watershed Management Commission (SCWMC) completed the following water quality improvement activities at Crystal Lake:

• Invasive Carp Management: SCWMC oversaw the removal of 9,641 common carp (about 28,000 pounds) from Crystal Lake from 2021-2024. Common carp are an invasive fish species that negatively impact water quality by stirring up and resuspending phosphorus-rich lake bottom sediments. Panfish, such as bluegill and yellow perch, will help control the remaining carp population by eating the eggs of spawning adults. 

• In-Lake Alum Treatment: Crystal Lake received in-lake treatments of a chemical called “alum” in September 2021 and September 2022. The two treatments are helping to improve water quality by limiting phosphorus levels and increasing clarity in the lake. Both treatments will remain effective and continue to support improved water quality for several years into the future.

• Crystal Lake Flocculation Treatment Plant: This year marked the twelfth year of operation of the Crystal Lake Flocculation Treatment Plant. This facility, located in Lakeview Terrace Park, is designed to remove phosphorus and other pollutants from the lake water. Tours of the Flocculation Treatment Plant will resume in 2025.

Lower Twin Lake Water Quality:

Lower Twin Lake is part of the Twin Lakes Chain, which includes Middle Twin and Upper Twin. The chain of lakes is not on the Minnesota Impaired Waters list, however, there are different water quality improvement activities happening on all three lakes to make sure the chain stays off the list. Robbinsdale is actively working on monitoring and removal of Curly Leaf Pondweed, an aquatic invasive species (AIS), from Lower Twin Lake. The SCWMC is also performing common carp surveys on all three lakes to determine the population. It will help decide if removal efforts are needed.

The adopted Stormwater Pollution Prevention Plan (SWPPP) is available to view for residents and all interested parties, as well as:

• The original Best Management Practices (BMP’s), 
• Additional BMP summary sheets
• Impaired Waters BMP Summary Sheet
• Twin and Ryan Lakes Nutrient TMDL
• Adopted Chloride TMDL BMPs 

Whenever building construction occurs within the City, site disturbance, excavation, and re-grading remove natural vegetation and expose underlying soils. As staff review plans for construction work, they ensure that best management practices (BMPs) will be used to limit site runoff. Some of these BMPs include silt fences, rock entrances, protection of storm drain inlets, and sweeping up sediment that leaves the site.

City staff regularly inspect active construction sites to ensure that these BMPs are all functioning and local water bodies are being protected to the maximum extent possible.

For more information on how to limit sediment erosion on construction sites, see: Construction Site Erosion Control Brochure.

• Join Lake Pledge! Protect your lake. Stop aquatic invasive species.

• Stop Aquatic Hitchhikers

• Zebra Mussel Fact Sheet

• Curly-leaf pondweed factsheet

• Purple Loosestrife

• Eurasian Watermilfoil Identification Card

• What you should do to prevent AIS from spreading | Minnesota DNR

• Help Protect Minnesota Waters

• Common Carp Information

• Common Carp | Minnesota Aquatic Invasive Species Research Center

• Invasive aquatic animals | Minnesota DNR 

• Invasive aquatic plants | Minnesota DNR

• Resources – Blue Thumb

• Building a rain garden

• Rain Garden Manual

• Smart Salting Training

• Educational resources for Smart Salting (S2)

• Illicit Discharge Detection and Elimination Brochure: City staff rely on the vigilance of residents to report illegal dumping and other “illicit discharges” that can contribute to undesirable material into our storm sewer system and eventually into our local water bodies. Anything in the storm sewer system that is not stormwater, even organic material such soil, leaves, grass clippings, and pet waste, has the potential to cause significant water quality problems in lakes and streams. If you observe signs that illegal dumping has occurred, please share your observation with City staff immediately

• Adopt-a-Drain - Minnesota: If you are passionate about protecting local waterbodies, consider adopting a storm drain near your home or business. By volunteering for fifteen minutes twice per month, you can help keep our water bodies clean by clearing leaves, trash, and other debris away from storm drains!

• Leaf and Grass Reminders