Water levels in the Mill Race water are lower than historic levels due to natural erosion at the inlet and from sediment deposited along the Mill Race channel.

Low water in the Mill Race stet quickly warmed up in the summer time, and this resulting in high temperatures and low dissolved oxygen for fish. This is especially problematic at the Mill Pond where the water is held back for a longer period of time.

A lack of sufficient riparian vegetation along the Mill Race also causes higher water temperatures because there is not enough shading on the water. The temperature increases downstream toward the Mill Pond in summer time along with turbidity from urban runoff.

High temperatures and low dissolved oxygen levels can be harmful to fish in the Mill Race. This is a potential problem for threatened Spring Chinook Salmon that need plenty of cool, high quality water.

DRINKING WATER

In addition to concerns about fish habitat, the Mill Race should be restored to maintain high quality water for the public water supply.

Springfield's drinking water comes primarily from groundwater obtained from public water wells operated by the Springfield Utility Board (SUB).

SUB does not use water directly from the Mill Race, but some of the water in the Mill Race percolates into the groundwater near water supply wells.

Improving water qualtity in the Mill Race is a good idea any way you look at it. Since water in the Mill Race recharges the groundwater for a portion of the city's drinking wells, improving water quality in the Mill Race will benefit both fish and people.