Updated analysis shows proposed stormwater mandates will cost San Bernardino County and cities $11 billion

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A landscape featuring a gently flowing river bordered by green and sandy banks. In the background, rolling hills contrast with a blue sky dotted with wispy clouds. — *Proposed stormwater requirements threaten to increase housing costs, strain city budgets and disproportionately affect disadvantaged communities across the region.*

An updated Beacon Economics analysis reveals that proposed stormwater requirements will impose an estimated $11 billion in costs on San Bernardino County and 16 of its cities over the next 20 years, unleashing a financial crisis that threatens to bankrupt cities, increase housing prices, gut public safety budgets, and disproportionately harm the region’s most vulnerable residents.

The Regional Municipal Separate Storm Sewer System (MS4) Permit overseen by the Santa Ana Regional Water Quality Control Board regulates stormwater runoff from urban areas. The proposed permit revisions would require sweeping new compliance measures that cities and the county say are both financially unworkable and environmentally unproven.

These concerns led to an outcry by Southern California counties and cities in 2024 when the permit was first discussed. After 15 months of silence and no effort at collaboration, the board’s 2026 update to the proposed MS4 permit was released about 60 days ago.

The Beacon analysis found the newest iteration of the proposed permit failed to reduce its huge costs in any material way. While the revised Tentative Order includes some minor improvements in implementation flexibility, the principal cost drivers remain unchanged as it seeks to apply an unproven standard that would force cities and counties to spend billions to divert and treat stormwater, which will drain rivers and streams that species depend upon and residents use for recreation.

The proposed permit presents an environmental paradox: the U.S. Fish and Wildlife Service has publicly voiced concerns that diverting stormwater flows to meet the proposed permit requirements will harm habitats for the Santa Ana Sucker Fish, which is officially listed as a threatened species under the U.S. Endangered Species Act. This raises the prospect that the new rules will cause the very environmental harm they purport to prevent.

Warning signs are also already visible elsewhere. In Los Angeles, a comparable stormwater mandate has failed to deliver required results despite a $300 million new tax to fund compliance, leaving agencies facing enforcement actions. San Bernardino County officials warn that arbitrary standards not yet proven by science, technology or real-world applications will produce the same outcome, leaving its cities unable to fund the basic services their residents depend on.

“We respect the Santa Ana Regional Water Quality Control Board’s mission and share the goal of clean water for our communities, but the cost impacts in this proposal are substantial, and we’ve seen in other regions that large investments in stormwater compliance haven’t translated into measurable water quality gains,” said Board of Supervisors Chairman and Third District Supervisor Dawn Rowe.

As the state wrestles with housing shortages and affordability issues, the Beacon report shows that the price of a new single-family home in San Bernardino County could potentially skyrocket by $26,000 to comply with the proposed permit, which require a costly stormwater treatment system to be installed on every single lot in a new home development, a requirement that does not exist today.

“Everyone agrees that clean stormwater is an important goal, but not at the risk of imposing financial hardship on cities, eliminating police and fire services, and pricing working families out of housing. The board has refused to seriously grapple with those trade-offs, and that is simply not acceptable,” said Board of Supervisors Vice Chair and Fifth District Supervisor Joe Baca, Jr.

The Beacon report also flags a key legal dimension: the U.S. Supreme Court’s 2025 decision in City and County of San Francisco v. EPA found that permit requirements must align with the statutory framework established by Congress. The court found permittees are not responsible for water quality outcomes they cannot control, yet the proposed permit does exactly that by imposing strict numeric standards for bacteria from nature as opposed to human sources. Federal law requires permittees to reduce pollutant discharge to the maximum extent practicable, not to achieve specific numeric pollutant concentrations.

As such, the proposed permit’s strict standards raise questions about whether the board is operating within its authority – heightened by the fact that no human illness has ever been connected to the county’s stormwater.

Despite concerns raised by environmental justice organizations, labor unions and dozens of elected and public works officials from across San Bernardino, Orange and Riverside counties, the Santa Ana Regional Water Quality Control Board is moving forward with a public hearing on the permit on Friday, July 24, at 9 a.m. at Orange City Hall. San Bernardino County and its cities are calling on elected officials, labor leaders and community advocates to attend and urge the board to provide alternative pathways to compliance instead of an unattainable standard that is driving costs.

“Our county achieves 99% compliance with non-bacteria numeric limits, and no agency in the nation has been as successful as we are in detecting and eliminating controllable sources of bacteria,” Baca said. “We should aim for a better path forward than investing billions in compliance measures that have not yet demonstrated consistent success in other regions.”

The 16 impacted cities include Big Bear Lake, Chino, Chino Hills, Colton, Fontana, Grand Terrace, Highland, Loma Linda, Montclair, Ontario, Rancho Cucamonga, Redlands, Rialto, San Bernardino, Upland and Yucaipa.

Local governments also object to the board process for developing the permit. Cities submitted 100 pages of comments to the Regional Board’s original Tentative Order in 2024. The board’s 440-page response to those comments was not released until June 2026 – two years later and just 15 days before the comment deadline, despite prior commitments to provide 90 days for review.

“This is not how sensible environmental policy is made,” Rowe said. “Fifteen months of silence followed by a 440-page data dump, broken promises on review timelines and surprise requirements that were never discussed. Given the astronomical costs, the board owes the communities it regulates a far more transparent and collaborative process.”

The Beacon report can be downloaded at https://bit.ly/4vzgHnQ.

Beacon Economics, a nationally recognized economic research and consulting firm, was engaged by the county to conduct an independent, data-driven analysis of the proposed regulations.

Additional County Update News – July 16, 2026