Seattle Children’s Hospital Rain Gardens


In an earlier post (Infiltration and Laboratory Testing Support Green Design), we described how rain gardens and bio-filtration swales are important to sustainability. The Seattle Children’s Hospital main campus expanded through the Building Hope program to meet the growing need in our region. Please enjoy these photos of the rain gardens when they were newly planted outside the new construction.




Wetland Banking 101

Edmonds Wetland 033

When the EPA and Army Corps of Engineers released their final rule on Compensatory Mitigation for Losses of Aquatic Resources in 2008 (2008 Rules), compensatory mitigation became as easy as going to the bank. A mitigation bank, that is. The 2008 Rules set out a hierarchy for mitigation that gives preference to larger-scale wetland restoration in a watershed context. Mitigation banks provide this ecological framework. Before 2008, mitigation banking was more expensive and riskier than concurrent mitigation. Cheaper, smaller-scale permittee-responsible mitigation was preferred even if it wasn’t the most ecologically beneficial.

A mitigation bank is a wetland, stream or other aquatic resource area that has been restored, established, enhanced, or preserved. This resource area is then set aside to compensate for future impacts to aquatic resources resulting from permitted activities. The value of a bank is determined by adding up the aquatic resource functions restored, established, enhanced, and/or preserved in terms of “credits.” Permittees who want to develop property get approval of regulatory agencies, to buy these credits to compensate for unavoidable wetland impacts.  Individual projects must still avoid and minimize impacts to wetlands before using a mitigation bank.

Many mitigation banks have been developed or are in process in Washington, Oregon, and other areas in the United States. So how’s the 2008 Rule being implemented and how is mitigation banking performing? There hasn’t been a national analysis of mitigation banking since the 2008 Rule, but expect another blog post when any analysis of the 2008 Rule or mitigation banking is released.

For more information, contact Jim Shannon, 425.775.4682.

Wetland mitigation bank guidance

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