System Configuration: The City Storm Drain system collects water through gutters, ditches, and catch basins, and conveys that water generally from west to east, by gravity, through canals and 12 inch to 60 inch storm mains to the pump stations on East Main Street. From there it is pumped into a canal along the south side of the Cache Creek Settling Basin. From there it flows into the Yolo Bypass, Tule Canal, and the Sacramento River. There are several detention basins in various locations around the City, that assist in dealing with peak storm flows.
System Design: The storm drain system is not adequately sized for the flows that it must handle. In the older sections of town, particularly west of East Street, the capacity is generally less than required for a "two year" storm (meaning a storm that has one chance in two of occurring each year-or a 50% probability of occurring each year). When the capacity of the system is exceeded, localized street flooding occurs until 3-4 hours after the rainfall subsides and the streets are again able to drain. While it may appear that the catch basin grates are blocked, the system is just overloaded and the excess water is "stored" in the gutters and on the street. A citizens Blue Ribbon Committee, appointed by the City Council, studied the situation in 1988 and reported that the benefits of upgrading the system (at a cost in excess of $10 million) was not justified. We will review this issue in our pending Storm Drain Master Plan update.
During periods of intense rainfall, City crews:
Residents can assist by: