Armstrong Lake Restoration - Oakdale Library Retrofit
The Washington Conservation District (WCD), Washington County, and South Washington Watershed District (SWWD) are partnering to retrofit water quality improvement practices at the Oakdale Library. The goal is clean water and the project will work toward the 101 pound phosphorus load reduction target for Armstrong Lake identified in the SWWD Watershed Plan. The project will also benefit Wilmes Lake, which is downstream from Armstrong and is impaired by excess nutrients. This project is also specifically identified in the Washington County Municipal Storm Sewer System (MS4) Retrofit Program and is considered a priority in the County.The retrofit design will address nutrient reductions through runoff volume control. It is anticipated phosphorus will be reduced by approximately 10 pounds, which is 10% of the total target load reduction for Armstrong Lake. Concept designs envision the installation of a large bioretention facility and multiple raingardens to treat runoff from the library parking lot and roof. As these are vegetation-based practices using many native plants, these practices will not only improve water quality, but also improve habitat, sequester carbon, and reduce heat island effect. In addition to the direct environmental benefits, retrofitting stormwater treatment at a County Library provides tremendous public visibility and education opportunities. The library is owned and operated by Washington County and long-term interpretation and education about the retrofit project will be provided at the facility.
(c) $3,000,000 the first year and $3,000,000 the second year are for nonpoint source pollution reduction and restoration grants to watershed districts, watershed management organizations, counties, and soil and water conservation districts for grants in addition to grants available under paragraphs (a) and (b) to keep water on the land and to protect, enhance, and restore water quality in lakes, rivers, and streams, and to protect groundwater and drinking water. The projects must be of long-lasting public benefit, include a local match, and be consistent with TMDL implementation plans or local water management plans. Up to five percent may be used for administering the grants (2011 - Clean Water Assistance); (b) $2,800,000 the first year and $3,124,000 the second year are for grants to watershed districts and watershed management organizations for: (i) structural or vegetative management practices that reduce storm water runoff from developed or disturbed lands to reduce the movement of sediment, nutrients, and pollutants or to leverage federal funds for restoration, protection, or enhancement of water quality in lakes, rivers, and streams and to protect groundwater and drinking water; and (ii) the installation of proven and effective water retention practices including, but not limited to, rain gardens and other vegetated infiltration basins and sediment control basins in order to keep water on the land. The projects must be of long-lasting public benefit, include a local match, and be consistent with TMDL implementation plans or local water management plans. Watershed district and watershed management organization staff and administration may be used for local match. Priority may be given to school projects that can be used to demonstrate water retention practices. Up to five percent may be used for administering the grants.
It is anticipated phosphorus will be reduced by approximately 10 pounds, which is 10% of the total target load reduction for Armstrong Lake.
Seven bioretention cells were installed in 2013 to remove 6.53 pounds of phosphorous, 12.85 pounds of nitrogen and 421.8 tons of sediment per year.