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TO: HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL
FROM: DIRECTOR OF PUBLIC WORKS
DATE: DECEMBER 21, 2004
SUBJECT: REPAIR OF THE TARAPACA STORM DRAIN
STAFF COORDINATOR: Ron Dragoo, Senior Engineer
The adopted FY 04 – 05 Budget includes funding to construct lining and miscellaneous point repairs to the City’s storm drains. Utilizing these funds, and responding to requests from nearby residents, video inspections of the Tarapaca Storm Drain were completed in early fall of 2004. The Tarapaca storm drain is a 400ft long 24" diameter
corrugated metal storm drain that conveys drainage from Tarapaca Drive to lower San Ramon Canyon – see attached exhibit map.
Because of the poor condition of the pipe, a complete video inspection could not be completed, however, based upon what was inspected it was concluded that the storm drain is deficient in several ways. The invert of the storm drain at several discrete locations was completely eroded and thus point repairs are required. The invert of the entire pipe is in a state of distress and thus the entire pipe needs to be lined. And finally the outlet of the storm drain had collapsed and thus needed to be reconstructed.
It was concluded that the best approach to address these deficiencies would be to make minor temporary point repairs to the pipe and construct a temporary outlet structure to sustain the system through the 04 – 05 storm season. It was planned that the reconstruction of the outlet structure and lining for this project, would be packaged together with needed repairs for two other storm drain system and advertised for bids after the storm season for construction this coming Summer.
During the course of completing the temporary repairs it was observed that there is erosion originating from this pipe may be impacting the stability of the eastern bank of the San Ramon Canyon. The erosion was observed to get worse during the most recent rains.
Based upon this observation, as well as the steepness of the terrain, the proximity of residential structures, the expected wet rainy season, and the history of the San Ramon Canyon, it was concluded that it would be more prudent to move forward with the needed repairs now. To move forward with the project in our traditional manner would require staff to prepare engineering plans, advertise the project, bring the project to the City Council to approve the plans and award a contract all in accordance with the Public Contract Code. Staff estimates that such a procedure would allow for commencement of construction no sooner than March 2005.
Public Contract Code Section 22050(a)(1) permits a public agency to procure necessary equipment, services and supplies for emergency repairs without competitive bidding. The governing body is required under Public Contract Code Section 22050(a)(2) to make a finding, based on evidence set forth in its minutes, that the emergency will not permit a delay, and that the action is necessary to respond to the emergency.
An "emergency" is defined in Public Contract Code Section 1102 as "a sudden, unexpected occurrence that poses a clear and imminent danger, requiring immediate action to prevent or mitigate the loss or impairment of life, health, property, or essential public services." Staff feels that this project qualifies as an emergency under the Public Contract Code because the erosion could reduce the stability of the eastern bank of the San Ramon Canyon. Instability of that slope would pose a clear and imminent danger to the private homes and other improvements that sit adjacent to the pipe. This situation should be addressed at this time so immediate action can take place to prevent the loss or impairment of these properties and the potential loss or impairment of life, health, or essential public services.
Approval of both recommended actions requires a four-fifths (4/5) vote of the Council under Public Contract Code Section 22050(a)(1). In addition, Public Contract Code Section 22050(c)(1) requires that when a governing body takes action under Section
22050(a)(1), it must review that action and reaffirm it by a four-fifths vote at each subsequent regularly scheduled meeting until the action is terminated. Accordingly, staff will place this item on each subsequent agenda until the project is completed.
This project is subject to review under the requirements of the California Environmental Quality Act (CEQA). Staff has determined that the project is exempt from the requirements of CEQA because the project is being undertaken as an emergency, and its scope is minor, consisting of lining an existing pipe, and reconstructing the pre-existing outlet structure.
Adopting the staff recommendation will authorize staff to proceed with urgently needed repairs to the Tarapaca Storm Drain. If approved the outlet structure will be reconstructed by city maintenance crews, and the pipe will be lined with a contract negotiated by staff. Efforts will be made to obtain two construction bids. The contract for the lining will be executed by the Mayor and City Clerk. The reconstruction of the outlet structure will be completed as a change order to an existing contract.
Costs for the recommended actions are estimated at $95,000 as follows:
Construct lining $ 60,000
Construct outlet structure $ 20,000
Engineering / Inspection $ 15,000
Total $ 95,000
Funding for the recommended actions is included in the adopted budget under miscellaneous storm drain repairs, and storm drain lining.
Dean E. Allison
Director of Public Works
Project Location Map
Storm Drain Location Map
Plans of outlet structure
Contract for storm drain lining
Notice of Exemption