WORKSHOP ITEM - Rebecca Haug, Water Resources Manager
Title
STORMWATER ENCROACHMENT
Background
The Clean Water Act was passed by the federal government in 1972 to clean and protect the nation’s lakes, streams, and rivers and was amended in 1987 because regulators and environmentalists realized that even every day activities of all residents had some impact on water quality. The amendment required the United States Environmental Protection Agency (EPA) to delegate permitting authority of the national stormwater program to the Minnesota Pollution Control Agency (MPCA). The national program is called the National Pollutant Discharge Elimination System (NPDES) permit program. The stormwater program was developed to reduce the pollution and damage caused by runoff from construction sites, industrial facilities and urbanized areas Municipal Separate Storm Sewer Systems (MS4s). In Minnesota, where water contributes to a high quality of life, extra attention has been directed toward cleaner water.
The city of Blaine has had a permitted program to address polluted stormwater runoff since March 10, 2003. The program is intended to reduce pollution from entering the storm sewer system and degrading water quality in Blaine and the cities and waters downstream. Preventative methods include controlling erosion on construction sites, regular maintenance of storm sewer systems, using phosphorus free fertilizers and keeping grass clippings and leaves out of the streets. The permit covers six main points:
• Construction Site Management
• Elimination of Illicit Discharges
• Pollution Prevention/Good Housekeeping
• Post Construction Best Management Practices
• Public Education
• Public Participation
One of the requirements of the permit is for the city to inspect and maintain its storm sewer system. The city has a complex stormwater treatment system which includes 8,800 catch basins and 1,200 manholes. These 10,000 structures are connected to 205 miles of underground storm sewer pipe. In most cases, stormwater from these structures is collected and discharged into one of the more than 500 man-made ponds throughout the city. These man-made ponds mimic natural systems but are designed to collect, store and treat stormwater by slowing the volume of flow, preventing flooding and allowing any suspended material and pollutants to drop out and settle to the bottom of the pond.
During inspections and communications from residents about the city’s stormwater ponds, there has been an increase in the number of buffers removed and the installation of docks and recreational uses around the city’s stormwater ponds. Stormwater ponds can pose safety hazards including strong currents during storm events, steep side slopes and drop-offs, unsafe winter ice and contaminated water and sediment.
Blaine City Code Article XI. - Stormwater Management, Division 3, Section 34-521 - Alterations to and use of public and private stormwater ponds, states the following:
• No alterations to shorelines or vegetation around stormwater ponds shall be allowed unless authorized by the city.
• Fountains or other circulating devices will not be allowed in stormwater ponds unless authorized by the city.
• Chemical treatment of stormwater ponds will not be allowed unless authorized by the city.
• Structures will not be allowed within the stormwater pond or protective buffer zone. These will include but not be limited to retaining walls, docks, piers, diving platforms, bridges, etc.
• Recreational activities, including but not limited to boating, swimming, fishing and skating are discouraged on all stormwater ponds.
• Dumping of yard waste materials in, on or around any stormwater pond is prohibited. Cattails growing in and around stormwater ponds may be cut with the permission and direction of the city.
(Ord. No. 10-2205, 5-20-2010; Ord. No. 18-2395 <https://library.municode.com/mn/blaine/ordinances/code_of_ordinances?nodeId=873061>, 1-18-2018)
The ponds along with the buffers, slow and reduce surface water runoff from adjacent land use and are effective at filtering pollutants such as fertilizers, pesticides, oils, pet waste, grass clippings and leaves. The installation of structures such as docks is a safety hazard because ponds are designed to fluctuate during rain events and docks can become unanchored and plug outlets of ponds increasing the chance of properties flooding.
Recommendation
Staff is seeking guidance on how the city council would like to enforce the city’s code regarding docks and removal of buffers.