In 1999, water managers in the Tualatin Basin completed an Integrated Water Resources Management Strategy, a framework for water users and resource managers to meet shared objectives. The conclusion of this effort was to focus on planning for future water supply.

Local water managers formed a partnership in 2001 and funded a Water Supply Feasibility Study (WSFS), a technical evaluation of options to meet water demands through the year 2050.

The WSFS identified a range of water supply options for meeting the future water supply needs in the Tualatin Basin. Several options were recommended for further evaluation including raising Scoggins Dam by 20 or 40 feet, constructing a new dam (Stimson Dam) immediately downstream of the existing dam, and an irrigation exchange pipeline from the Willamette River.

The study also concluded that conservation, reclaimed water, aquifer storage and recovery (ASR) and planned Portland Bull Run system improvements should be included in any project components. The study was completed in 2004.

Water Supply Feasibility Study   WSFS Final Report 2004 PDF 4 MB Integrated Water Resources Management Strategy Final Report PDF 572 KB Evaluation Criteria 2002 PDF 16 KB Source Options Cost Comparison 2003 PDF 64 KB Source Options Evaluation Summary 2003 PDF 132 KB Spring 2003 Update PDF 836 KB Spring 2002 Update PDF 76 KB     Appendices to the WSFS Final Report   Biological Basis for Fish Passage PDF 126 KB Fish Passage Feasibility Study PDF 4.84 MB Fish Passage Waiver Procedure PDF 110 KB Habitat Survey PDF 641 KB Hagg Lake Biological Resources PDF 6.84 MB Hagg Lake Recreation Study PDF 2.3 MB Hydraulic Modeling PDF 566 KB Hydrology Analysis PDF 1.4 MB Irrigation Exchange Pipeline PDF 1.92 MB Sain Creek Tunnel PDF 14.3 MB Scoggins Dam Alternative Site PDF 1.47 MB Scoggins Soils and Genealogy PDF 252 KB Supply Options Evaluation Summary PDF 83 KB Tributary Below Scoggins Creek PDF 987 KB Trout Redd Survey PDF 147 KB WSFS Evaluation Criteria PDF 83 KB Water Demand Projections PDF 233 KB