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Home My WebLink About2019-12-05; 2019 Kelly Channel Emergency Repair; Gomez, PazTo the members of the: CllY COUNCIL Date •~Is 119 CA ~ CC _:k CM ~ COO ~ DCM (3) ...::£. Dec.5,2019 Council Memorandum To: Honorable Mayor Hall and Members of the City Council From: Paz Gomez, Deputy City Manager, Pub ~ W?rks Via: Elaine Lu key, Chief Operations Officer Re: 2019 Kelly Channel Emergency Repair {city of Carlsbad Memo ID# 2019142 This memorandum provides information related to storm damage that occurred to a concrete channel drainage facility adjacent to Kelly Drive and the subsequent emergency repair effort. Attachment A includes photographs of the location with storm damage. Background On Nov. 20 and 21, 2019, the San Diego region received a significant storm event. After the storm, city staff conducted preliminary post rain inspections of the city owned drainage facilities to check for potential damages and assess performance of the storm drain systems. A concrete channel facility located adjacent to Kelly Drive, between El Camino Real and Park Drive, has required emergency repairs in past winters with the latest occurring in November 2018. The previous year's repair appears to be in good condition at this point, but a different section of the channel has collapsed in a manner similar to the previous failures for this facility. A five-foot long by four-foot wide hole is visible in the concrete lining of the channel and a void underneath the concrete section is noticeable. The hole is located within a city-owned drainage easement over the properties of 4866 and 4868 Park Drive. Currently, the hole is completely contained within the drainage easement, but may encroach into private properties with future rain events. On Nov. 25, 2019, city staff notified the San Diego Regional Water Quality Control Board (San Diego Water Board), California Department of Fish and Wildlife (CDFW), and U.S. Army Corps of Engineers (USACE) regarding the site condition, proposed emergency repair plan and intent to apply for the necessary emergency permits. Based on staff's assessment, an estimated 117 cubic yards of material has been displaced from underneath the concrete channel lining. City staff has begun preparing repair plans and emergency permit applications for resource agency approvals. Similar methods from the 2018 repair are being proposed due to its proven success and preferred construction methods by the resource agencies. On Nov. 26, 2019, a qualified contractor was contacted to estimate the cost of repair work. City maintenance crews installed a temporary cover over the hole in the concrete lining to minimize the damage by preventing surface water from entering the void, in anticipation of rain events over the Thanksgiving holiday. Water may still enter the void through subsurface flows. Public Works Branch Faraday Center 1635 Faraday Avenue I Carlsbad, CA 92008 I 760-602-2730 Honorable Mayor Hall and Members of the City Council Dec. 5, 2019 Page 2 On Nov. 27, 2019, city staff completed the propqsed repair plans and submitted the permit applications for emergency repair to the resource agencies. The city received follow up correspondences from the USACE and San Diego Water Board on the same day. These agencies confirmed the application is complete and have begun to process their respective permits. No correspondence to date has been received from CDFW. In 2018, CDFW ruled the project repair was operation law, meaning the project did not require a permit from their agency; however, a notification was required and fulfilled with the submittal of the permit application. A similar ruling is expected with this year's repair. Next Steps City staff is standing by for issuance of Regional General Permit Number 63 from the USACE. This permit vehicle is pre-approved by the San Diego Water Board allowing for expedited issuance for emergency situations such as this repair. Staff will begin to process a minor public works contract in the interim, so work can readily begin upon issuance of the permit. Once the work begins, staff anticipates several days of pumping water from the void before concrete forms can be placed in the channel. Once the void is ready for concrete, "No Parking" signs will be placed at least 72 hours in advance of construction on the east side of Kelly Drive, just south of Hillside Drive. An estimated five parking spaces will be temporarily lost so that concrete trucks delivering the material can park near the channel's access gate. The installation of concrete is expected be completed within one day. Parking impacts will not occur during the dewatering phase of work. · Upon completion of the repair, staff will complete the follow-up protocols from the USACE. Compensatory mitigation is not expected as impacts to habitat will be avoided with this year's repair. USACE has requested a monitoring biologist to be present on-site during the repair to confirm habitat impacts are avoided. This will complete the third emergency repair to the channel since 2010. Each repair has occurred in different locations of the facility. A capital improvement project to replace the channel in its entirely was included in the fiscal year 2019-20 budget. Extensive technical studies to support the design and environmental approvals are expected to prolong the procurement of the project. As a result, emergency or localized repairs may be required in the interim due to the future storm events. Attachment: A. Photographs Showing Storm Damage to Concrete Channel Drainage Facility Adjacent to Kelly Drive cc: Scott Chadwick, City Manager Celia Brewer, City Attorney Babaq Taj, Interim Transportation Director Amanda Guy, Deputy City Attorney Honorable Mayor Hall and Members of the City Council Dec.5,2019 Page 3 James Wood, Environmental Manager Hossein Ajideh, Engineering Manager Honorable Mayor Hall and Members of the City Council Dec. 5, 2019 Page 4 ATTACHMENT A Photographs Showing Storm Damage to the Concrete Channel Drainage Facility Adjacent to Kelly Drive Figure 1: Concrete channel failure east of 4866 Kelly Drive. 5' x 4' hole in channel lining is visible. The 14-foot long fracture to the right of hole is upstream limit of void underneath the concrete lining Honorable Mayor Hall and Members of the City Council Dec. 5, 2019 Page 5 Figure 2: View of void from the eastern slope of channel. Property line of 4866 (right) and 4868 (left) Kelly Drive can be seen in background