When the South Washington Watershed District (then called the Cottage Grove Ravine Watershed District) was first established in 1993, its primary objective was to protect against flooding in Woodbury and Cottage Grove. Since then, the district’s boundaries have expanded along with its mission, which now includes protecting and restoring area lakes and the Mississippi and St. Croix Rivers, conserving groundwater resources, and helping local communities to adapt to a changing climate with more frequent, higher intensity storms.
Encompassing 110 square miles at the confluence of the Mississippi and St. Croix Rivers, the South Washington Watershed District includes all of Cottage Grove, St. Paul Park, Newport, Denmark Twp. and Grey Cloud Twp., as well as portions of Woodbury, Oakdale, Lake Elmo and Afton. Included in this area are twelve lakes and 2,400 acres of wetlands.
New development continues to be one of the biggest challenge facing the watershed; what was once prairie, savanna, and forest has now been converted to suburban development, and farming has radically changed the landscape even in the parts of the district that remain rural. These changes mean more water running off the land when it rains, less water soaking in to recharge shallow and deep groundwater aquifers, and more pressure on the groundwater resources people use for drinking and irrigation.
When the South Washington Watershed District was first formed, a large segment of the watershed covering Oakdale, Lake Elmo and Woodbury was draining to one little lake – Bailey Lake, which had no controlled outlet. Localized flooding was already a problem in some neighborhoods, and the local communities knew the problem would get worse as development continued. To protect homes and businesses, the watershed district purchased 250 acres of land near the outlet of Bailey Lake and constructed what is now known as the Central Draw Storage Facility – essentially a large, bowl shaped meadow that can temporarily fill with water like a small lake when Bailey Lake overflows. Currently, the district is proceeding with later phases of the flood-prevention project, scheduled to be complete in 2020, which involves building a series of pipes and dry streams to carry overflow water from the Central Draw down to the Mississippi River in the event of a 100 or 500-year mega-storm.
Along with a heightened risk of flooding, changes in land use in southern Washington County have degraded water quality in area lakes as well. Rain and melting snow wash off of farm fields, roads and parking lots, carrying sediment, nutrients and pollutants into ditches and storm sewers that connect to area waterways. As a result, the lakes have less fish than they used to and suffer from algae blooms during the summer.
During the past twenty years, city, state and watershed district rules have helped to reduce polluted runoff from construction sites and limit stormwater runoff from developed areas as well. As a result, water quality in area lakes and wetlands is no longer getting worse. Now, the South Washington Watershed District is increasingly looking for opportunities to retrofit already developed areas and pursuing “in-lake” strategies to remove pollution already in the water as well. One such project was a neighborhood retrofit near Colby Lake, in which the district built 25 residential raingardens to capture and clean stormwater runoff from local streets. Industrial sized raingardens can also be seen at the Bielenberg Sports Center and the South Washington County Service Center.
The South Washington Watershed District is currently developing a new 10-year plan that will guide its work from 2016-2026. The Watershed District board will review recommendations from staff and advisory committees at a special meeting on Tuesday, June 23, 6-8pm at the Woodbury Public Works building, and they are also hoping to get feedback from people who live and work in the watershed. To provide input, attend the upcoming meeting or contact John Loomis at 651‐714‐3714 or email@example.com. Additional information is available at http://www.swwdmn.org.