LADWP Stormwater Capture Master Plan

Client

Los Angeles Department of Water and Power

Services Provided

Surface water resources, Local supply development, Strategic Planning, Policy/ordinance development, Public outreach and stakeholder participation, Multi-agency coordination, Stormwater management, Multi-benefit project development, Climate resiliency planning and analyses, Funding/resource valuations

Aerial view of downtown Los Angeles with tall skyscrapers, city buildings, and a rail yard with numerous train tracks and shipping containers in the foreground.

Location

Los Angeles, California

Project Practice Areas

Water & Wastewater, Environmental Management, Water and Natural Resources

Type of Facility

Local water supply

Project Specifics

The Los Angeles Department of Water and Power (LADWP) has invested heavily in increasing the amount of local stormwater captured for water supply through projects like the Hansen Spreading Grounds Enhancement Project, the Big Tujunga Dam Retrofit, and the Woodman Avenue Stormwater Capture Project.

The Department has also invested internally, developing the Watershed Management Group – staffed by six engineers and a Water Works Engineering Manager within the Water Resources Division – to provide technical leadership on behalf of the Department. Now, the Department has developed a Stormwater Capture Master Plan to completely understand the potential stormwater that can be realistically and reliably captured to augment the City’s water supply portfolio. The Master Plan investigates existing and proposed programs, policies, and projects to better manage runoff from individual parcels and from the larger watersheds flowing into, and within, the City.

Geosyntec Scope of Services

Geosyntec synthesized existing and planned actions by the Department, the LA County Flood Control District, other City agencies, and local non-governmental entities that impact stormwater to ensure that the Master Plan complements and enhances significant stormwater capture efforts already in progress. In addition, Geosyntec calculated the amount of stormwater generated by the subwatersheds tributary to and within the City of Los Angeles. Geosyntec also investigated multiple constraints associated with capturing stormwater for beneficial use to determine the realistic amount of stormwater the City can reliably depend upon and the impact that this amount of stormwater capture would have on surface water quality improvements and peak flow attenuation in the Los Angeles River.

Notable Accomplishments

Following the inventory and model development tasks, Geosyntec compiled and analyzed an extensive list of potential stormwater capture alternatives (policies, ordinances, projects, programs) to truly compare the strategic and business case aspects for each project, individually and as part of a larger suite of alternatives. The Geosyntec Team has developed centralized and distributed stormwater capture programs and projects to compare alongside the existing list, including the Tujunga and Pacoima Spreading Grounds project. Geosyntec crafted an implementation plan from the suite of selected alternatives to create a roadmap for the Department that capitalizes on political, physical and financial opportunities.