Bend finding savings in sewer plan revisions

The results of Bend’s initial sewer modeling were announced this week, and the news is good, city officials said Friday. Engineers see the potential to save tens of millions of dollars on the total cost for needed sewer system upgrades, compared to earlier plans.

Master planning for Bend’s sewer collection system has been underway since last year, guided by a 17-member citizen panel — the Sewer Infrastructure Advisory Group.

The panel was appointed by the City Council to pinpoint the most urgent priorities for sewer system upgrades, and to find opportunities for cost savings.

In recent months, the engineering work has focused on optimization modeling, which uses thousands of computer simulations to find the right mix of pipes, pumps, storage and treatment for Bend’s future sewer system.

The initial findings confirm that two major sewer upgrades already underway are needed under any future scenario.

The Southeast Interceptor is a gravity pipeline that will serve most of Bend’s neighborhoods in the south and southeast. The Colorado Lift Station is the other critical project, needed to transport wastewater from Bend’s west side.

But two other preliminary findings point to more opportunities for cost savings.

Bend could avoid construction of almost six miles of pipeline construction by building underground storage to hold flows during wet weather.

Another opportunity is decommissioning dozens of pumps, which are costly to operate and maintain. With over 300 pumps in service, Bend has more pumps than any other city in Oregon — and more than New Orleans, which is below sea level.

Advisory Group members will present the initial optimization findings to Bend City Council on Wednesday, Dec. 4. The group is also offering to give presentations to neighborhood associations, civic groups and other organizations. Community members can learn more at bendoregon.gov/SIAG

Optimization modeling will continue through next March. Further in-depth analysis will look for ways to phase-in sewer improvements to reduce impacts of rate increases for customers. Project cost estimates and effects on sewer rates will be analyzed in the spring, city officials said.