The last collection system evaluation was completed in 1997 and since then the population has increased by about 10,000 people. Periodic evaluations of the system allow the City to better monitor trouble spots, identify deficiencies, and make accurate cost estimates for improvements.
Precipitation that falls in Hermiston becomes stormwater and is managed in several ways, including surface runoff into open bioswales, underground injection and drainage when sandy soils allow, and collection and pumping to Hermiston Irrigation District facilities. This complex system has had to keep up with City growth into new areas as environmental regulations have changed. In many cases, when bioswales and underground injection facilities are overwhelmed, the water ends up at old pump stations.
As the Sewer Collection System Evaluation is being done, it makes sense to develop a comprehensive inventory of stormwater systems to more efficiently manage this process in to the future.