The complexities of developing a new water source require Hillsboro Water (HW), under the leadership of the Utilities Commission (UC), to plan well in advance of the need. Even though Hillsboro's second source of water may not be online for many years, the choice for the second source needed to be made now, so that planning and development could begin. Developing a new source will take at least another decade. HW began working in 2004 on securing additional water supples to ensure that future customers have an adequate, safe, and reliable source of water to meet demands for the next 50 years and beyond..
As a partner in theTualatin Basin Water Supply Partnership (TBWSP) , Hillsboro initially worked with the other TBWSP partners to explore raising Hagg Lake 40 feet as a long term water supply source for the citizens of Hillsboro and greater Washington County. The project seemed to be viable and was progressing through the planning process, but then the Bureau of Reclamation, who owns the dam, conducted a seismic study. The results of the study indicated major repairs are required to bring the dam to current seismic standards. When added together, the total project cost increased from an estimated $250 million, for initial expansion facilities, to almost $1.3 billion for a larger expansion plus seismic rehabilitation costs. Due to this escalation in costs, HW decided to widen their exploration to a range of alternate source supply options. The study would either confirm Hagg Lake as still the best option, or identify another solution for rate payers that would be a better balance between cost and risk.
In order to continue long-term planning efforts, and in consideration of the partnership, Hillsboro Water formed a multi-agency Technical Advisory Committee (TAC) to assist in the exploration. Members from the TBWSP, who are part of the TAC, included City of Forest Grove, City of Beaverton, the Tualatin Valley Water District, and Clean Water Services. The study not only identified additional source supply alternatives, it also paired up those additional alternatives against the existing alternatives, including the raising of Scoggins Dam, and conducted side-by-side comparisons. Using the results of the study, the Commission selected the Mid-Willamette as the preferred option, and a more-detailed study is ongoing to further refine costs and project challenges.
The purpose of this website is to provide information to Hillsboro Water customers and interested parties about the various source options that were considered, the designation of the mid-Willamette as the secondary source, and the process to develop that second source to serve Hillsboro's next generation of customers.