Our staff works on cutting edge projects for which out-of-the box thinking is required. Herrera conducted a modeling study of a low-impact development subdivision in Seattle, WA at a time when modeling procedures had not yet been developed region-wide. The objectives of the modeling were to support engineering of the stormwater management facilities, including bioretention swales, porous pavement, compost amended soils, and gravel pocket parks; and to predict whether the development would meet state and local regulatory requirements. Our modeling for that project was subsequently included in the flow control modeling section of the Puget Sound Action Team Low Impact Development Technical Guidance Manual for Puget Sound.

Our recent advanced hydrologic and hydraulic modeling studies include dam break analysis, dam enlargement design, design of on-site and regional capital facilities, and development of local and state flow control policy. Our engineers regularly use the following models: HEC-RAS, HEC-GeoRAS, HEC-HMS, XP-SWMM, WWHM2, KCRTS, HSPF, MGS Flood, StormShed, DAM BREAK, Infoworks-CS, and HY8. We also have extensive CAD and GIS capabilities and routinely integrate these technologies into our modeling studies.

Key Projects

• Low Impact Development Technical Guidance Manual by Puget Sound Action Team, WA – Contributing author
• High Point Revitalization – City of Seattle, Seattle Public Utilities
• Ozette River and Lake Ozette Modeling Study of Large Woody Debris – Makah Indian Tribe
• Thornton Creek Water Quality Channel – Seattle Public Utilities
• Rainwise Stormwater Incentives Package to encourage onsite low impact development features – Seattle Public Utilities
• South Park Conveyance Improvements – Seattle Public Utilities