Stormwater capture drain reimagines flood management and sustainability

 A stormwater capture project, known as the Beaumont MDP Line 16, is forging a new path for conservation and flood protection in Southern California. A $7.6 million joint venture between the Beaumont-Cherry Valley Water District (BCVWD) and Riverside County Flood Control and Water Conservation District, this underground storm drain balances flood mitigation in Cherry Valley, California, with stormwater capture for regional groundwater replenishment. It collects 150 to 500 acre-feet of stormwater annually — enough water to supply as many as 900 local families for a year. 

Extended periods of drought have strained groundwater resources in California, particularly during the drought’s later years. Groundwater accounts for up to 60% of the state’s total water supply during dry conditions. It is a critical component of California’s water storage. 

While some stormwater seeps into the ground to naturally recharge our aquifers, much of it runs to the ocean and there are opportunities to maximize the potential of this natural resource. 

Stormwater aids in groundwater replenishment

Stormwater fits well into the state of California’s current goal to increase groundwater replenishment by 500,000 acre-feet of potential recharge capacity. The Department of Water Resources (DWR) has so far awarded $68 million to 42 groundwater recharge projects that provide nearly 117,000 acre-feet of potential recharge capacity. Using stormwater to replenish groundwater supply is a key part of this vision. 

With recent atmospheric rivers pelting Southern California with heavy rainfall, the Beaumont MDP Line 16 project protects a region especially susceptible to flooding. Without the drain, stormwater would continue to flow along local roadways into Marshall Creek, to be lost downstream. 

This water is eventually lost to the sea, where it becomes unusable without advanced desalination. Lost stormwater is a major untapped resource nationwide — 59.5 million acre-feet of stormwater goes uncaptured across the United States every year, according to a recent report by the Pacific Institute. California ranks ninth in states with the greatest stormwater runoff potential, with approximately 2.27 million acre-feet of urban area runoff yearly. 

As the Fifth National Climate Change Assessment announced in November, the American Southwest can expect periods of reduced precipitation countered by periods of extreme rainfall and flooding. At the same time, traditional water sources, such as underground aquifers and fresh water from rivers, streams and snowmelt, are growing increasingly unreliable. Population growth, agriculture demand and climate change are creating intense strain on water resources. Amidst this climate backdrop, stormwater capture is a vital tool to protect communities from flooding and conserve water for recycling, water reuse and groundwater replenishment. 

As California navigates these extreme weather conditions, the Beaumont MDP Line 16 project proves an essential means of conservation. Storm runoff deposits into BCVWD’s recharge ponds, in turn filling the Beaumont groundwater basin. The basin offers a large storage capacity, allowing the district to shore up its underground supply bank in preparation for dry spells and water shortages. 

“The Beaumont MDP Line 16 project is leveraging the abundant precipitation California has experienced in recent years to support long-term regional sustainability,” Daniel Slawson, vice president of the Beaumont-Cherry Valley Water District Board of Directors said. “The wet years have brought dramatic drought relief to California, and we’ve found a way to turn that stormwater into a dependable supply for customers.” 

Project garners industry-wide recognition 

The Beaumont MDP Line 16 project received two notable awards in 2023 and is a current contender for state-level recognition. 

The project received the Outstanding Flood Control Project of the Year Award from the American Society of Civil Engineers (ASCE) Los Angeles Section and an Outstanding Flood Management Project accolade from the ASCE San Bernardino and Riverside. The project is now under consideration for a Region 9 Award, which encompasses all of California. 

Nominations were made by the ASCE’s branches, Younger Member Forum, Life Member Forum, technical groups, committees and individual members. 

 As an organization dedicated to advancing infrastructure leaders, the ASCE accolades highlight the work of BCVWD and Riverside County Flood Control and Water Conservation District. 

“BCVWD was honored to receive industry recognition for our work on the Beaumont MDP Line 16 project,” John Covington, president of the Beaumont-Cherry Valley Water District Board of Directors said. “Ultimately, the community is the biggest beneficiary of this engineering effort. The 59,000 customers in our service area are protected from flood impacts and can depend on a strengthened water supply thanks to this project.” 

An infrastructure solution years in the making 

The culmination of more than 10 years of ambitious effort, the Beaumont MDP Line 16 project represents a well-executed partnership between two regional stakeholders. 

BCVWD and Riverside County Flood Control and Water Conservation District had previously worked together on successful flooding and debris flow projects. The two agencies were aligned on the opportunity to protect residents in an area susceptible to flooding from even small amounts of rain and conserve local water supplies. Through this work, they promoted regional water security now and into the future. 

While BCVWD brought deep groundwater conservation knowledge to the table, the Riverside County Flood Control and Water Conservation District contributed expertise in flood management and environmental preservation. The team constructed an innovative storm drain and relocated five existing waterlines in the process. 

In addition to local partnerships, the project was supported by the DWR and the Santa Ana Watershed Project Authority. It received $1.2 million through the Prop 84 Integrated Regional Water Management Implementation Grant. 

“This project is a testament to the power of local partnerships,” Director Covington said. “We’re proud of the steps toward sustainability achieved through concerted teamwork. The Beaumont MDP Line 16 project team is committed to the safety of our community, the preservation of our natural resources, and our joint ability to support a water-secure future.”