s part of the Bear Valley Community Services Main Gate Improvements, it was recognized that improvements needed to be made to the drainage system in the immediate area. Several problem areas needing addressing, including the private driveway and street crossing on Buttercup Court behind the police station, and the crossing under Bear Valley Road. Currently, storm water surface-flowed across a private driveway and into a 48” culvert under Buttercup. This area was fairly flat and silted in often, covering the street and private drive.Further down the drainage channel, under the police station entry way off of Buttercup, are four 24” culverts. This is actually a bottleneck for the flow as these pipes are not capable of carrying the same amount of CFM as a 48” pipe. Finally, the 48” pipe under Bear Valley Road was collapsing and had lost a lot of its capacity.
ANALYSIS
Improvements are designed to handle a 25-year recurrence interval, and include the following design elements:
- Buttercup Court: A riprap channel will be installed parallel to the private driveway to channel the flow of water to Buttercup. It will no longer flow across the private driveway. A 72" drop inlet will be installed to aid in future maintenance. A 48" CSP pipe will be installed across buttercup and discharge into the current drainage channel.
- Police Station Entrance off Buttercup: The four 24" CSP pipes will be replaced by a 48" CSP, and appropriate riprap and head walls will be installed.
- Bear Valley Road: The collapsing 48" CPS will be replaced with the same size. The area is wide enough to accommodate 3 lanes, so this pipe will be replaced one lane at a time to allow two-way traffic to continue in and out of the gate.
- Drainage Channel: The entire open drainage channel from Buttercup to Bear Valley Road will be reshaped and graded to better fit the design characteristics of the project
FISCAL IMPACT
The total amount of the Gate drainage phase of the project is not to exceed $267,000.