By Patty Z. Kouyoumdjian, Executive Officer
The Lahontan Regional Water Quality Control Board, known as the Lahontan Water Board, is a state agency whose mission is to protect surface and groundwater uses for current and future benefit of all Californians. The board has seven members appointed by the governor and confirmed by the Senate. Staff offices are located in South Lake Tahoe and Victorville.
Implementing a number of federal and state regulatory programs, board decisions directly or indirectly affect most all residents within the Lahontan Region. The Lahontan Region encompasses the Great Basin portion of California. It extends from Oregon south to the San Gabriel and San Bernardino Mountains and eastward from the crest of the Sierra Nevadas to Nevada. Within San Bernardino County, numerous board actions are taken to protect and improve the state’s waters. This article’s focus is the Stormwater Program.
Stormwater Program Requirements
Statewide general orders (e.g. permits) exist for three main stormwater program categories; industrial, construction, and municipal. Permit links are on the State Water Resources Control Board website at: http://www.waterboards.ca.gov/water_issues/programs/stormwater/. Coverage under all permits is obtained through the SMARTS database, which can be accessed at that website.
Construction permit coverage is required for any land disturbance greater than one acre. Note that disturbed area, not project size, is the governing factor. Additionally, project components forming a larger plan of development must be considered together. Minimizing sediment transport impacts is the primary permit objective. For each project a site-specific Stormwater Pollution Prevention Plan, or SWPPP, must be prepared by a Qualified Stormwater Developer. It must identify appropriate Best Management Practices, or BMPs, that will be installed and maintained by a Qualified Stormwater Developer for both the construction and post-construction periods.
The water board’s key objective is ensuring that effective post-construction BMPs are in place at the time permit termination is granted. The permit requires that the post-construction runoff is equal to or less than pre-construction runoff and that runoff does not cause downstream effects, including erosion or modification of drainage patterns, swales or stream channels. A site-specific hydrology calculation must be done to verifythat the post-construction BMPs will be effective at meeting this requirement. While there are a wide range of BMPs that may be proposed, the Lahontan Water Board promotes BMPs appropriate to the arid high desert climate, using Low Impact Development, or LID, principles discussed below. Effective post-construction BMPs must be proposed in the project design. Numerous termination requests have been declined by the water board where post-construction BMPs were not in place. To speed the termination process, proponents should include photographs showing the periphery of the construction site, especially runoff locations. Photographs of the interior drainage features, unless integral to post-construction BMPs such as prefabricated infiltration chambers, are less important.
Industrial permit coverage is required based on industry type or Standard Industrial Classification (SIC) codes. For manufacturing facilities coverage is required for SIC codes 20XX through 39XX and 4221 through 4225. Permitted facilities must prepare and implement a SWPPP that identifies appropriate BMPs. The permit requires stormwater runoff sampling from Qualifying Storm Events. Staff has inspected many industries in the Victor Valley that have ineffective BMPs or conduct operations in or near ephemeral waterways, causing adverse effects to waters. Identifying and requesting modified practices and improved stormwater management will be the focus of future inspections. The permit includes two new options for enrollees. A No Exposure Certification may be obtained if all industrial materials and activities areprotected by a storm-resistant shelter. A Notice of Non-Applicability signed by a registered professional engineer may be submitted if a facility is engineered to contain the maximum historic precipitation event or is located where there is no hydrologic connection to waters of the United States.
Municipal permit coverage is required for the Town of Apple Valley; Cities of Barstow, Hesperia, and Victorville, and portions of the County of San Bernardino. In addition to controlling pollutants in stormwater runoff from municipal activities (shops, yards, streets, etc.), municipalities must adopt ordinances providing legal authority to control pollutants (including sediment) into and from the municipal storm system. Other program areas include public outreach and education, illicit discharge identification and elimination, construction site controls, and post-construction BMP requirements. The permit requires new projects to capture stormwater from the 85 percentile 24-hour precipitation event. Effective maintenance is the key to ensure post-construction BMPs continue to protect water quality.
Low Impact Development, Stream and Wetland Impacts
In the earliest project design phase, applicants should assess and evaluate how site conditions such as soils, vegetation, and flow paths should be considered in the placement of buildings and impervious surfaces to reduce adverse impacts to surface flow paths, water quality and wildlife habitat. Environmental documents should identify how the project incorporates Low Impact Development, or LID, principles to protect water quality. The High Desert has unique rainfall and stormwater runoff patterns. LID practices should be customized for each individual site to preserve pre-development hydrology by limiting impervious surfaces (i.e, paving), promoting stormwater infiltration, minimizing land disturbance, and incorporating structural BMPs such as pervious pavement, infiltration galleries, energy dissipation, etc. Water board staff have observed many older projects have radically alteredthe ephemeral wash downstream environment by increasing runoff velocities and volumes, causing excessive sediment erosion and sediment deposition in lower-lying areas, burying wildlife and riparian habitat. Incorporating LID principles in future new and redevelopment projects will protect and improve our unique desert environment and water quality for our future.
Proposition 1 Grant Funding Resources
A new opportunity to obtain stormwater project funding is available through Proposition 1 grants. This requires applications to reference an adopted Stormwater Resources Management Plan that identifies projects on a watershed basis. That plan may become a component of the Mojave Water Agency’s Integrated Regional Water Management Plan and can be used to support grant requests. The water board encourages local municipalities to cooperate and cost share in preparing this plan.