City pact clears way for Oswego Lake sewer line


After months of negotiations, the city of Lake Oswego and Lake Oswego Corp. reached an agreement Tuesday on an estimated $100 million project to replace an interceptor sewer pipeline in Oswego Lake.

The agreement provides for a six- to seven-month, 16-foot winter drawdown of the main lake beginning September 2009.

This allows the city to begin construction activities early, lowering project costs and risks and allowing for refill of the lake prior to the summer recreation season, according to Stephan Lashbrook, interim city manager.

The Lake Oswego City Council approved the agreement and authorized staff to complete final documents to implement it.

The agreement governs the timing and the duration of the drawdown of Oswego Lake. It also outlines locations, terms and conditions governing easements required for placement of the new pipe and for construction and maintenance access.

'Our primary goal was to make sure that sewer overflows will be reduced in the timeliest way possible,' said Bill Wiley, Lake Corp past president and board member. 'It was also important to preserve the recreation season for the majority of our shareholders and fundamental rights of property owners along the shoreline. I think this agreement is a win-win for both the city and the Lake Corporation.'

Other provisions of the agreement include:

• Work in the main canal will occur in the summer through construction of a cofferdam at the mouth of the canal allowing emptying of the water. Winter work in the canal is not feasible because of issues relating to storm water runoff, project risk and floodway regulations. Emptying of the canal will begin in March 2009.

• Easements will be provided at no cost to the city for the new pipeline in the lake as well as for access points for maintenance and construction.

• Construction periods will be from 7 a.m. to 8 p.m.

• Future drawdowns of the lake will be allowed following the construction period as necessary for maintenance and repair of the pipeline.

'I'm pleased that we've reached an agreement that is fair to the residents and ratepayers of Lake Oswego and for those who live on the lake,' said Mayor Judie Hammerstad. 'This agreement allows the interceptor project to start in a timely manner so we can prevent sewage overflows in the future.'

The interceptor is a sewer pipe that will run 14 to 21 feet below the surface of Oswego Lake.

The current interceptor was built in the 1960s and is too small and structurally unsound.

Prolonged rain can cause the system to back up, resulting in sewage overflows. The city plans to have the interceptor replacement project completed by spring 2010.