Watershed Modeling Services for King County, Washington
Client: King County Department of Natural Resources, Seattle, WA
The King County Department of Natural Resources, Water and Land
Resources Division retained AQUA TERRA Consultants to provide
water resources modeling services to develop a water quantity and
quality analysis models for two topographic basins - the
Green-Duwamish and the Lake Washington-Ship Canal watersheds.
These models support the two major projects, the
Green-Duwamish Water Quality Assessment (GD WQA) and the
Sammamish-Washington Analysis and Modeling Program (SWAMP). They
are integrated components of an overall modeling system of
both watersheds and major receiving water processes including
hydrodynamics, water quality, and bio-dynamics within the Duwamish
River and Lakes Sammamish, Washington, and Union.
The primary purpose of the watershed water quality and quantity
models are to support the GDWQA and SWAMP teams by simulating at a
tributary level, surface and subsurface flow and associated
physical, chemical, and biological loads to major receiving waters
- the Green River (excluding areas above the Tacoma Public Works
Division) and Duwamish Estuary for the GDWQA and the Lakes for the
SWAMP under a range of land use and infrastructure scenarios.
Additional purposes of these models are to provide a general tool
for watershed analysis, management and educational outreach
components of SWAMP and GDWQA, King County’s ESA-response, aquatic
resource protection, stormwater management programs, and
ecological and human health risk assessment.
The watershed modeling services were accomplished
cooperatively by King County staff and AQUA TERRA through an
on-call services arrangement in terms of various work orders.
Sammamish-Washington Analysis and Modeling Program (SWAMP).
The purpose of this project was to evaluate the impact of urban
and rural areas on the hydrology and water quality of the
Sammamish and Lake Washington watersheds. This project involved an
assessment of the existing King County modeling effort in this
study area and linkage to the hydrodynamic models representing the
downstream lakes (Sammamish and Washington). Strategies for water
quantity and quality modeling were developed along the
selection of the appropriate modeling tools. Water quantity and
quality models were developed as needed and calibrated and
validated prior to the investigation of different land use and
operational scenarios in the watersheds.
Green-Duwamish Water Quality Assessment (GD-WQA).
The purpose of this project was to evaluate the impact of urban
and rural areas on the hydrology and water quality of the Green
and Duwamish watersheds. This project involved an assessment of
the existing King County modeling effort in this study area and
linkage to the hydrodynamic models representing the downstream
estuary of Elliott Bay and Puget Sound. Strategies for water
quantity and quality modeling were developed along the
selection of the appropriate modeling tools. Water quantity and
quality models were developed as needed and calibrated and
validated prior to the investigation of different land use and
operational scenarios in the watersheds.
