East Garden Grove-Wintersburg Channel (OCFCD Facility No. C05) from upstream Warner Avenue to downstream Goldenwest Street.

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1 Facility. C05) from upstream Warner Avenue to Lead Agency: Agency: Project Director: Address: Orange County, Public Works, Infrastructure Programs, Capital Programs Sam Ali 300 N. Flower Street Santa Ana Phone: Cell Phone: General Project Information: Name: East Garden Grove-Wintersburg Channel (OCFCD Facility. C05) from upstream Warner Avenue to downstream Goldenwest Street. Description: 1 of 6

2 Facility. C05) from upstream Warner Avenue to The existing channel is an earthen bottom trapezoidal levee channel. It is 70 feet wide at the base with wall height varying between 12.6 to 10 feet. It has 1.5:1 side slopes (horizontal: vertical) lined with riprap rocks. Constructed in 1960s, it was designed to convey 65% of the 25-year peak discharge. Access roadway is located on both sides of the channel for maintenance vehicular access. The proposed improvement includes ground modification to the levees/maintenance road, construction of a tertiary system of soil mixed columns armed with sheet piles on both sides creating a channel 146 feet wide with 18 feet high walls and providing adjacent residents three lines of defense against flooding. The improvement includes but is not limited to excavation of the existing embankment. The regulatory permits process for this project is on going and has been a long process up to this point; the levee channel slopes are eroding and have become dilapidated to the point that the maintenance road is unsafe to drive on. The ground modifications to the levee may continue with or without regulatory permits depending on the severity of erosion on the levee caused by future storms however, excavation on the existing embankment will require regulatory permits and may not proceed until acquired. The land use element surrounding this channel segment consisted of a mixed residential single family to the northwest and low to medium high density residential and general commercial neighborhood to the southeast. The general area is under Zone A of the FEMA FIRM panel no C0234J dated December 3, Plans and engineering specifications will be prepared for the construction of the improvement of the 4,993-foot segment of the EGGW Channel for the specified project limits. Regulatory permits will be applied for the US Army Corps of Engineers, the Regional Water Quality Control Board, and Department of Fish and Game. Goals/Objectives: To increase the level of flood protection for the residents within the C05 flood plain by reducing or eliminating potential for personal injury and property damage due to flooding. Improve this reach of the flood control channel to be able to convey the 100-year storm design discharge and eventually reduce the FEMA Special Flood Hazard Area (SFHA) aka 100- year floodplain to containment within the channel, thus eliminating the high cost of obtaining mandatory flood insurance. Utilize a flood control improvement alternative that fits within the existing right-of-way constraints. Prioritize phasing of the construction of the proposed channel improvements to maximize benefits for the watershed. Need: 2 of 6

3 Facility. C05) from upstream Warner Avenue to The East Garden Grove-Wintersburg Channel (EGGWC), OCFCD Facility. C05, is an approximately 11.8 mile long regional flood control facility in north/central Orange County. The EGGWC is currently the largest flood threat in Orange County. The EGGWC system was designed and built in the 1960s to convey 65% of the 25-year peak discharge (approximately a 10-year storm event). EGGWC is inadequate to convey the 100-year storm frequency design discharge and does not provide the desired level of regional flood protection as mandated by the Federal Emergency Management Agency (FEMA) for adjacent properties to be outside the inundation area of the 1% annual chance flood event. A segment of the EGGWC, from upstream Warner Avenue to downstream of Goldenwest Street is in need of improvement to convey the 100- year storm runoff. Its limits are from Station upstream of Warner Avenue to downstream of Goldenwest Street at Station This 4,993-foot channel segment is currently an earthen bottom trapezoidal section. It is lined with riprap stones and has a base width of 70 feet and wall height varying from 12.6 to 10 feet. The existing channel is deficient; capacity is 65% of a 25-year storm event. Meets statutory eligibility gates of 2015 IRWM Grant Funding: IRWM Goals: Safely co-manage flood protection and water conservation. Maintain quality of life. IRWM Type OWOW Plan Project Type: Construction Latitude: Project Location: Longitude: Project is construction improvements to Orange County Flood Control District (OCFCD) Facility. C05, East Garden Grove- Wintersburg Channel located in Orange County, City of Huntington Beach Benefit Zone Area (mi2): 82 Project Benefits: Benefits Water supply reliability, conservation and water-use efficiency Stormwater capture, storage, cleanup, treatment and management Removal of invasive species; wetlands creation or enhancement; acquisition, protection and restoration of open space n-point source pollution reduction, management, monitoring 3 of 6 Applicable

4 Facility. C05) from upstream Warner Avenue to Groundwater recharge and management Contaminant and salt removal, reclamation, desalting and conveyance to users Water banking, exchange, reclamation and improvement of water quality Multipurpose flood and stormwater management programs Watershed protection and management Drinking water treatment and distribution Ecosystem and fisheries restoration and protection Where Benefits Accrue: Jurisdiction: Explanation: Watershed/Su b-region: Explanation: Synergies: Multiple Communities The benefactors are residences and businesses from Cities of Huntington Beach, Westminster, Fountain Valley, Garden Grove, and Santa Ana. Entire Watershed The East Garden Grove-Wintersburg Watershed has a drainage area of 17,984 acres. It is within the C Watershed which has a drainage area of 68,164 acres. The OCFCD s goal and plans work towards FEMA & National Flood Insurance Program s (NFIP) efforts in protecting property and lives from the threat of flood damage from storms. When the project has been completed, the OCFCD submits a Letter of Map Revision (LOMR) to FEMA to revise Flood Insurance Rate Map (FIRM) to reflect the floodplain as removed or diminished to containment within the channel facility alleviating the costly mandatory flood insurance premiums imposed on the benefactors, the residents and businesses from that community (s). Benefits to Disadvantaged Communities (DAC) and Native Tribal Communities (NATC) 4 of 6

5 Facility. C05) from upstream Warner Avenue to 100% DAC: Portion DAC: DAC %: % NATC: Portion NATC: NATC %: 0 Project area benefiting DAC (acres) : Describe DAC and NATC Benefits: The FEMA Flood Insurance Rate Map will be revised to reflect the 100-year to be contained in channel alleviating the costly mandatory flood insurance premiums imposed on the DAC. Human Right to Water: N/A Environmental Justice: N/A Project Partners: Agency Name Contact Phone Collab Planning Direct Funding In-Kind Service Co-Manager Project Funding: Category Amount Percent Total Project Cost $22,000, Requested OWOW 2015 Funding $ Match Contribution $22,000, Local Contribution $22,000, Federal Contribution $ In-Kind Contribution $ Other $ SRF Loan $ Annual O&M Costs: $440, Funding Secured: Explain: 5 of 6

6 Facility. C05) from upstream Warner Avenue to this project is on the Flood Control Capital Improvement Project Plan which is a list of prioritized projects through a 7-year period. This channel system is one of OCFCD s highest priorities; it is one of several segments of the channel system to be constructed. Funds for flood control capital improvement projects, including operation and maintenance come mainly from property taxes and state contributions; this project is listed on the third tier from being budgeted. O&M Funding Secured: Explain:. Funds for flood control capital improvement projects, including operation and maintenance come mainly from property taxes and state contributions. Operation and maintenance is ongoing for this channel system and is budgeted every fiscal year. Project Criteria: Criteria Metric Description Flood Risk Reduction e+009 $ NA Project Status: Project Status: Preliminary design (30%) completed Est. Complete Date: 06/30/2018 Est. Operational Life (years): 100 Agency Constructed Similar Projects : CEQA Status: In Progress Date: 06/30/2017 NEPA Status: t Applicable Date: NA Project Attachments: Type FileName Project Complete: Project Active: 6 of 6