|The Storm Drain Master Plan (Master Plan) is a capital infrastructure planning document that evaluates the City's existing storm drain system and identifies potential areas of system deficiency. The Master Plan is a tool that can help the City plan and budget for future storm drain improvements, as well as coordinate construction with other major capital improvement projects, such as major street improvements. The current Master Plan was last updated in 1992 and is nearing the end of its expected 20 to 30 year useful life as a planning document.
There have been few storm drain improvement projects in La Habra over the past decade, mainly due to a lack of sufficient funding to plan and build major system renovations. The primary, if not sole, source of funding for storm drain improvements is the City's General Fund. Since the General Fund is also the primary source of funding for municipal operations, including public safety, park/street maintenance, building/planning, and other programs and services, there is seldom remaining unbudgeted resources available to earmark for capital projects, including storm drain system improvements. Some of the more recent storm drain projects that the City has been able to fund included the relocation of catch basins at multiple locations around town as part of larger street intersection widening projects and the installation of storm drain screens through the use of grant proceeds.
In order to help coordinate the updating of the Master Plan, the City retained the services of Willdan Engineering (Willdan) which has staff with expertise in this area. The Master Plan prepared by Willdan identifies existing drainage deficiencies in the City that do not conform to current engineering design practices and which may, if left unaddressed, contribute to localized flooding during major rain events. The Master Plan also contains recommendations which, if implemented, could reduce the chance for flooding and/or eliminate existing deficiencies within the City's storm drain system. Recommended drainage improvements are prioritized in the report and include estimated costs for the necessary improvements. Due to the Storm Drain Master Plan's size, it is on file with the City Clerk and the City Engineer, but can also be viewed on the City of La Habra's website on the Engineering page (link provided as Attachment 2). The total cost estimate for all recommended improvements to the citywide storm drain system is approximately $46.9 million dollars. Again, it is important to note that at this time, the City's General Fund is the only available source of funds to make improvements and/or repairs to the local storm drain system.
Based on the findings in the attached report, the City's storm drain system currently lacks the capacity necessary to convey storm water runoff produced by a ten-year storm event, which is a storm of such intensity that it can be expected to occur only once a decade. Despite drought conditions that hampered the Southern California region over the past decade, the City has nevertheless experienced more than one ten-year storm during this time and, in fact, has experienced at least one storm of greater intensity which caused minor to moderate flooding in the community.
The Master Plan identifies many inadequacies in the City's storm drain system due to changes in hydrology criteria methods that were updated in the 1980s, after much of La Habra's storm drain system had already been constructed. The predominant type of pipe used in the City's storm drain system is reinforced concrete pipe, which has an approximate service life of 75 years. Another type of pipe that was commonly used in the past was corrugated metal pipe, which has a much shorter service life of approximately 45 years. Considering that much of the City's storm drain system was constructed between 1960 and 1990, a large portion of the City's system is nearing, or has surpassed, its expected useful life span. The City has already experienced storm pipe failures along City streets over the past several years, including key portions of Imperial Highway, Beach Boulevard, Sierra Vista Street, and Russell Street, which have required emergency repairs exceeding $600,000 in unbudgeted cost.
Due to the age of the City's storm drain system and the cost associated with repairs, the Master Plan includes a recommendation that a repair/replacement program be developed and implemented to regularly replace or rehabilitate damaged sections of the City's storm drain system. Below are seventeen major storm drain projects, listed in order of priority as determined by City and Willdan staff:
Capital Improvement Program Costs
||Euclid St.- Coyote Creek to Pinehurst Ave., east on Pinehurst Ave. to Main St.
||Monte Vista- Coyote Creek to La Serna Ave.
||Walnut Street- Coyote Creek to Highlander Ave.
||College St- Coyote Creek to Stearns Ave.
||Russel St.-Valley Home to Roanoke St. Downstream imp. not in estimate (in Whittier)
||Bedford- Superior to Stearns and Colfax from Stearns to Whittier, Whittier west to Ellie
||Lateral 2- Stearns Ave. SD from Colfax St. to Juanita St. then on Juanita to Dot Ave.
||Lateral 1- Rockinghorse Ln. from Whittier/Concourse to Rockinghorse Ln./Arbolita Dr.
||Cypress St.- Coyote Creek to Francis Ave
||La Plaza Dr- Coyote Creek to La Habra Blvd. to Hanline Way
||Dorwood Ave./ Viviwood Place- 50' s/o Patwood Ave. to Imperial Creek Channel
||Idaho St.- South City Limits to Auburn Way
||Sturbridge Dr.- Waverly Terrace to Imperial Hwy. and east to Beach Blvd.
||Imperial Hwy.- West of Idaho St. to Beach Blvd. and north on Beach to Coyote Creek
||Euclid St- Imperial Channel to Avenida Santa Anita
||Lambert Road- Walnut Street to Vista Grande Park
||Mountain View Street at Coyote Creek
In addition to the cost to construct these projects, it is recommended that additional funds be budgeted annually to rehabilitate segments of the system that may be functioning nominally, but that are reaching the end of their service life. In order to identify potential problems areas, the storm drain system is inspected regularly and, when conditions warrant repair/replacement, staff conducts repairs or replacements on an as-needed basis depending on the availability of funds. While staff estimates that it will cost at least $1 million per year to fund the reconstruction of the existing system over time as segments reach the end of service life, staff also recommend that an additional $5 million be allocated for future construction to address major system failures or repair needs.