As Anchorage becomes more urbanized, water quality can deteriorate due to:
The Design Criteria Manual provides Municipal drainage standards and policies for designers of new land developments, re-developments, roads, and drainage projects. These standards and policies are designed to decrease flooding and erosion, and to reduce adverse impacts in compliance with the requirements for stormwater management. For additional guidance, see:
Because urban development can change the flow of streams, degrade water quality, cause erosion, and more, the goal of Low-Impact Development (LID) is to mimic the natural water cycle that existed at the site before it was developed. LID is an innovative stormwater management approach with a basic principle that is modeled in nature: manage rainfall at the source using uniformly distributed, decentralized, small-scale controls. In essence, it works to establish a more natural water cycle. The Municipality has published a Low Impact Development Design Guidance Manual that includes ideas for engineers and developers.
In addition to developing rain gardens and implementing stream setbacks, there are a number of municipal LID projects in the works or under consideration: projects involving roadways, parking lots, runoff stream outfall disconnections, and the Anchorage School District.
The Municipality sponsors a Rain Gardens program for residential and commercial property owners to develop small or large rain gardens. Rain gardens with contributing water source area greater than 2,000 sq. ft. qualify for a cost-share reimbursement of up to $5,000. In 2011, 33 rain gardens were constructed throughout Anchorage. Visit the Anchorage Rain Gardens Website for more information.
Stream setbacks are another way that we protect our waterways and watersheds. Keeping new development at a prescribed distance from waterways helps avoid detrimental impacts. Streams are protected by several sections of the Anchorage municipal code, which regulate a variety of activities near streams, lakes, floodplains, and other watercourses.