Lower Mission Creek Flood Control Project – Reach 1A, City of Santa Barbara, California – APWA Project of the Year
DRC was the prime consultant on the American Public Works Association’s (APWA) Project of the Year in 2012: the Lower Mission Creek in the City of Santa Barbara, California, for improved flood control. It was widened 35 to 55 feet, from State Street, near the city’s pier, to Mason Street.
Our team prepared designs, plans, and specifications for constructing this first reach sponsored by the County of Santa Barbara with USACE oversight. The project required significant environmental mitigation and constraints on surrounding habitat areas, fish habitat design, permitting, and oversight by a biologist. Final design material consisted of the Hydrologic Engineering Center-River Analysis System (HEC-RAS) model hydraulic design confirmation, environmental design confirmation, unique pile/wall design, levee design, channel design based on USACE criteria, structural calculations, contract drawings, specifications, MII (MCACES) quantity/cost estimate, DrChecks system project reviews, and Engineering Considerations and Instructions for Field Personnel (ECIFP).
The APWA cited several factors for the award:
As prime consultant, DRC engineers developed a Preliminary Design Report to address alternatives for flood control measures in the U.S./Mexico border communities of Nogales, AZ, and Nogales, Sonora. The study coordinated and reviewed existing data and literature, hydrologic and hydraulic models for Arroyo Nogales, delineated three concept designs and cost estimates for structural improvements to reduce the potential for flooding, project schedules for major phases of design and construction activities for each alternative, and listed potential environmental requirements.
DRC reviewed existing information and previously published documents pertaining to flood damage, runoff, and flood control measures in Nogales, Sonora and Nogales, Arizona. The information contained existing watershed scale topographic mapping for use in rainfall-runoff analyses, topographic mapping for use in hydraulic analyses and preliminary design of alternatives, topographic cross section data for Arroyo Nogales in Nogales Sonora. Information included historical stream flow data on Arroyo Nogales and tributaries and regional discharge frequency relationships for the project area in the United States and Mexico. Our engineers attended meetings with IBWC Staff at the Nogales Project Field Office to discuss flooding issues in the Nogales area, potential project alternatives and coordinated with pertinent offices at the Los Angeles District, including the Plan Formulation Branch (Planning Division), Hydrology and Hydraulics Branch (Engineering Division), Engineering Design Branch (Engineering Division).
DRC developed the with-project hydrologic models by modifying the existing Corps without-project models for concentration points in Nogales, Sonora to include detention facilities, diversions, pumping, and channel improvements in the three alternatives. We performed hydraulic analyses for the 5-, 10-, and 25-year events for the three alternatives.
DRC prepared conceptual designs of the proposed features in the three alternatives which included enough detail in regards to location, dimension, foundation, and materials so that the element could be evaluated in terms of performance at the given flood level, overtopping, and long term stability; so that DRC can prepare cost estimates for construction, operations, and maintenance of each alternative. DRC also prepared cost estimates for each alternative.
DRC presented the preliminary project results to the USACE, the International Boundary and Water Commission (IBWC), and stakeholders at two project meetings in Nogales. These meetings determined the final outcome. DRC coordinated with IBWC to identify requirements for environmental compliance documents and other project permits for work in Mexico, and any applicable National Environmental Policy Act (NEPA) requirements for each alternative. DRC also prepared a comprehensive report that documents the approaches, methodologies, alternatives, and results of the analyses.
DRC performed a geotechnical assessment—including drilling, logging, sampling, and permitting—as prime consultant to allow the U.S. Army Corps of Engineers Geotechnical Branch evaluate alternative approaches and associated costs for railroad embankment under-crossings, which were integral to the Rio de Flag Flood Control Project in Flagstaff, AZ. DRC earned an “Outstanding Performance Rating” from the Corps of Engineers for this project.
DRC provided traffic control and underground utility clearances; coordinated and provided all necessary city/state/railroad permits, including right-of-entry on Burlington Northern and Santa Fe Railway Company (BNSF) land. DRC ensured compliance with all applicable regulations with the Department of Water Resources and Burlington Northern and Santa Fe Railway Company requirements including obtaining specialized insurance and permits to ingress and work on railroad land.
DRC was responsible for verifying the underground utility avoidance and a project-specific Safety and Health Plan that focused on drill rig stability and worker safety on slopes, in forested areas, around overhead wires, near active railroad tracks, and within 25 feet of the railroad tracks’ centerline. We prepared Traffic Control Plans which took under consideration the use of the adjacent Chamber of Commerce parking lot as the ingress-egress point. It was critical that DRC maintain access and a good relationship with the Chamber since it would be very costly and would cause rigorous traffic control issues to use other alternatives in the area.
DRC performed contract and field management, including all work on city land with the city, preparing a cost-effective traffic control plan, issuing notifications and locations of drilling, and obtaining permits. DRC coordinated closely with the Corps of Engineers, maintaining accurate records of all work, including work schedules that were often ten-hour days.
As prime consultant, DRC prepared and submitted an Environmental Assessment (EA), a Biological Assessment (BA), and a Cultural Technical Report (CTR), evaluating impacts for the proposed construction of base-wide flood repair projects and subsequent operations that will facilitate the ongoing mission of Marine Corps Air Station (MCAS), Camp Pendleton, CA. The scope of work included an EA and BA to address the proposed construction of several flood repair projects, an apron expansion, demolition of the fuel farm facility, and an 11,000-ft road built along the air station’s perimeter.
The BA assessed the project’s direct, indirect, and cumulative impacts on all listed/proposed species and critical habitat. The BA also proposed suitable mitigation measures for all impacts to federally listed or proposed endangered species and their habitats to lower project impacts below a level of significance. Its level of detail met all requirements of the Endangered Species Act of 1973 (as amended) and the U. S. Fish and Wildlife Service regulations to support a formal Section 7 Consultation, if necessary.
The CTR included a records search, a pedestrian survey, a Phase I inventory study, a technical report, and a description and impact assessment of the cultural resources at each project location.