HRA conducted cultural resource studies and analysis of alternatives for Combined Sewer Overflow (CSO) Reduction projects in the Henderson, Genesee, Windermere, and Madison Park Basins along the west side of Lake Washington in the City of Seattle. Eight of the nine locations required compliance with State and Local legislation while one required compliance with Federal. Work included peer review, archaeological and architectural inventories, and a National Register of Historic Places (NRHP) evaluation and determination of effect on Seward Park. The Park was found eligible for the NRHP and some of the contributing elements would be affected by the project alternatives. Our peer review ultimately led to HRA’s revision of City of Seattle’s Director’s Order 2-98.