Agenda

Return

C. 10

To:	Contra Costa County Flood Control District Board of Supervisors
From:	Julia R. Bueren, Public Works Director/Chief Engineer
Date:	September 20, 2016

Contra

Costa

County

Subject:

APPROVE and AUTHORIZE execution and filing of claim against the EBMUD for damages arising from a water transmission main break.

APPROVE	OTHER
RECOMMENDATION OF CNTY ADMINISTRATOR	RECOMMENDATION OF BOARD COMMITTEE

Action of Board On: 09/20/2016

APPROVED AS RECOMMENDED

OTHER

Clerks Notes:

VOTE OF SUPERVISORS

AYE:

John Gioia, District I Supervisor
Candace Andersen, District II Supervisor
Federal D. Glover, District V Supervisor

ABSENT:

Mary N. Piepho, District III Supervisor
Karen Mitchoff, District IV Supervisor

Contact:	Tim Jensen, (925) 313-2390
cc:	Mike Carlson, Flood Control Paul Detjens, Flood Control Tim Jensen, Flood Control Jason Chen, Special Districts Mario Consolacion, Flood Control Catherine Windham, Flood Control

I hereby certify that this is a true and correct copy of an action taken and entered on the minutes of the Board of Supervisors on the date shown.
ATTESTED: September 20, 2016
David Twa,

BY:	, Deputy

RECOMMENDATION(S):

APPROVE and AUTHORIZE the Chief Engineer, Contra Costa County Flood Control & Water Conservation District (District), or designee, to execute and file a claim against the East Bay Municipal Utility District (EBMUD) for damages arising from a 24-inch water transmission main break in the Walnut Creek area.

FISCAL IMPACT:

Staff costs to prepare and file the claim will be nominal. There is no fee to file the claim. Staff intends to seek reimbursement from EBMUD for the cost of preparing the claim. (Unreimbursed costs to be funded by Flood Control Zone 3B.)

CONSEQUENCE OF NEGATIVE ACTION:

If the District does not file a timely claim, the District may be unable to recover the cost of repairs from EBMUD.

BACKGROUND:

EBMUD owns, operates, and maintains a 24-inch water transmission main located along the route of the Iron Horse Trail west of South Broadway in Walnut Creek. The water transmission main passes underneath a portion of a reinforced concrete box culvert that is part of a side discharge channel of the San Ramon Bypass Channel. The District owns, operates, and maintains the side discharge channel. The interior of the box culvert is approximately 15 feet high and 20 feet wide.

On or about October 14, 2015, the water transmission main broke underneath the box culvert, and approximately 72,000 gallons of water was discharged through a hole in the main. The water discharged from the main washed away structural backfill material that had provided support to the box culvert, created voids, and caused a sinkhole to develop on the adjacent Iron Horse Trail. EBMUD notified District staff of the incident by telephone at approximately 11:55 a.m. on the morning of October 16, 2015. At approximately 1 p.m. the same day, District staff arrived at the scene to inspect the damage and observed that temporary repairs had already been made to the sinkhole and that the voids were not visible. District staff was advised by EBMUD personnel, and observed, that the sinkhole had been backfilled with roadway base rocks. EBMUD personnel did not provide District staff with any evidence that the structural backfill had been replaced or that all the voids had been filled.

The box culvert supports a portion of South Broadway, the Iron Horse Trail and a sound wall, and various utility lines are located overhead. The roadway base rocks placed by EBMUD cannot provide adequate support to this box culvert on a long-term basis. At this time, however, District staff does not know the full scope of repairs that will be needed or the cost of those repairs. District staff requested EBMUD staff to submit a plan for repairs to the box culvert, and EBMUD staff initially agreed with this request, but EBMUD did not submit a plan. In August 2016, EBMUD staff advised that the District was in a better position to prepare the repair plan and make the repairs and that the District would need to file a claim for reimbursement.

Accordingly, District staff recommends that the Board approve and authorize the execution and filing of a claim against EBMUD under the Government Tort Claims Act for an amount to be determined. The filing of the claim will preserve the District’s right to file a future civil action for damages arising from this incident should that be necessary.