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Minnehaha Creek: In the 1800s, Minnehaha Creek boasted so many fish that farmers could spear pitchforks full! Development drained wetlands, and built streets, buildings, and lawns so that rain flushes rapidly down storm drains and through the creek in a flood. Between rains, Minnehaha Creek today often dries up completely. Presettlement Vegetation Presettlement Vegetation Presettlement and Forest Maps Key: Brown – Oak Savannah Yellow – Prairie Dark Green – Big Woods Light Greens - Wetland Forest Cover Today Habitat Action Why Does Native Habitat Matter? Americans increasingly appreciate the beauty of native prairies, wetlands, and forests. Rising real estate prices next to such “amenities” are one measure of that change. (Schools also value native habitat for field study research.) Native habitat also brings real economic benefits: • Slows runoff, allowing half or more of rainfall to infiltrate into the ground where water is cooled, cleaned of pollutants, and then released slowly into waterways. • Prevents erosion, keeping phosphorus and other nutrients out of waters. (Excess phosphorus triggers algae “blooms” in late summer.) • Nurtures insects and animals that control pests. • Shelters species needed to pollinate crops and flowers. • Cools the air in summer and blocks cold winds in winter, saving on energy bills. Wetlands Today Oak Savannah remnant on the Mississippi River in Minneapolis. Photo from National Park Service. There are practically no prairies left in the watershed to map! Fact sheet produced by Cairn & Associates with support from Minnesota Environmental Trust Fund, and Twin Cities Metropolitan Council, Environmental Services. Effect of Development on Runoff Peak Flow Root Depths of Native and Non-native Grasses Post-development Rate – Flood and Dry-out Pre-development Rate Even Distribution Time Do Small Bits of Habitat Really Matter? A well-designed “rainwater garden” captures runoff from a larger area – often including roofs and driveways – then uses native plants to speed infiltration. A study at Iowa State University found that native grasses and mature forest absorbed five times as much runoff in inches per hour as row crops or turf. (L. Bharati, K. H. Lee, T. M. Isenhart, and R. C. Schultz. 2002. “Soil-water infiltration under crops, pasture, and established riparian buffer in Midwestern USA,” Agroforestry Systems 56: 249-257. Kluwer Academic Publishers.) With more than 99% of prairies, and most wetlands and forests gone, every remaining piece is precious. What Can I Do? • • • • Help identify remaining parcels of wild lands and support their legal protection as parks or open spaces. Mobilize volunteers to help restore existing habitat: collect seeds, raise seedlings, plant and cultivate native plants. Reconstruct native habitat in nature study area and/or rainwater gardens. (Takes a long-term commitment!) Follow the links from the Watershed Action web site to plan and to get expert help. http://cgee.hamline.edu/watershed/action Rainwater Garden – Before and After Como Park, St. Paul Photo by Laura Bates, Ramsey County Conservation District