A City Struggling to Meet the Demand for Water
Los Angeles has struggled to manage stormwater pollution for decades, but a new plan attempts to turn foe into friend and harness the power of the rain, turning it into a valuable resource for the city. Last month, the Los Angeles Department of Water and Power (LADWP) further discussed their long-awaited solution to address the dire situation of stormwater pollution in the South Coast basin. This article provides an overview of the LADWP’s stormwater mitigation strategy and future goals.
Many leaders in environmentally-conscious states and cities are leading committees to find novel ways to combat the side effects of climate change. Los Angeles is one of those, with Mayor Eric Garcetti tackling the elephant in the room: water demand in the nation’s second largest city. Facing the remnants of a half-decade long drought and climate change threatening to desertify the city, a practical groundwater repurposing plan would not only alleviate pollution in runoff, but it promises to also address the city’s lack of renewable water resources.
Founded in 1902, the LADWP supplied water to the fast-growing town of Los Angeles. Today, it acts as the biggest municipal utility in the nation with 25 billion gallons of runoff emptied out of the Los Angeles River in January 2017 alone, and stormwater runoff remains a prime environmental concern. Enter the Sustainable City Plan, which acts as the roadmap for a rebate program over the next two decades. If successful, the plan aims to double the amount of water collected from potable aquifers through various projects and policy changes from the current 35,000 acre-feet per year to at least 65,000 acre-feet per year (1 acre-foot equals 326,000 gallons).
The Sustainable City Plan
The Sustainable City Plan’s objective is outlined in the revamped Stormwater Capture Master Plan (SCMP) and identifies practical incentives for the widespread capture and use of stormwater as a new water supply resource. According to the Plan’s 2015 estimate, capturing runoff from impervious urban surfaces during the city’s notoriously infrequent rain events has the potential to increase water supplies as much as 630,000 acre-feet, equal to the amount of water used by Los Angeles annually. Consequently, by routing water away from urban rivers, the Plan’s secondary motive serves the purpose of reducing the overall harm of surface water pollution in California.
The Master Plan also includes recommendations on other stormwater capture projects, policies, incentives, and new ordinances throughout the City of Los Angeles. L.A. Mayor, Garcetti, authorized the construction of a $39 million facility aimed at cleaning up polluted stormwater runoff from LAX airport. This facility will add 60 million gallons of water into the groundwater basin each year to replenish the water supply. The incentive programs under SCMP encourage homeowners to install large water harvesting tanks or cisterns under depressions in their garden and provide rebates to terraform land into rain gardens by helping to direct runoff during rainfall into capture basins.
Stormwater Incentive Program for Industrial Facilities
Larger commercial and industrial facilities could see significant rebates for integrating larger water-permeable surfaces as long as the LADWP requirements discussed below are met. By 2035, a hopeful estimate under the Plan would see the total (industrial, commercial, and residential) capture of anywhere from 100,000 to 200,000 additional acre-feet of stormwater annually, enough to supply two households with water for a year.
Although programs dedicated to diverting runoff and boosting groundwater supplies sounds relatively easy, capture projects are not easy to fund. Even the expansion of small areas, such as a city park, into a sizable capture area for the infiltration of stormwater, costs millions of dollars.
The plan’s eligibility for a proposed project takes into account the parcel ownership, a completed ISRP (Industrial Sites Refuse Program) application, and a final review and approval stage. Next, the project evaluation phase concerns the quantification of maximal stormwater capture potential, which requires hydrologic analysis and determination of the average yield. Lastly, approved projects must enter into an agreement with the LADWP and comply with all terms, including treatment requirements, installation of flow meters, and public disclosure of all information submitted.
Some of the challenges posed by the Plan include:
- Environmental impact analysis,
- Water rights,
- The cost of monitoring,
- Regulatory jurisdiction between local and state requirements.
The LADWP has been hosting periodic stakeholder meetings to engage interested facility managers, industry representatives, and environmental and community-based organizations in discussions of the proposed program that would provide incentives for industrial facilities to capture, treat. and infiltrate and/or reuse runoff. Interested parties should visit the LADWP website for upcoming events and more developments.
More implementation details on LADWP’s stormwater plan can be found here.