LA Regional Water Quality Control Board Set to Adopt Draft

Commercial, Industrial and Institutional Stormwater Permit

July 30, 2026

Dear NAIOP, 

On July 23, 2026, the LA Regional Water Quality Control Board (the “Board”) officially approved the Commercial, Industrial, and Institutional (CII) Stormwater NPDES Permit for properties that have five acres or more of impervious surfaces on parcels located within two watersheds in Los Angeles County.[1] The two watersheds included in the permit are:

• The Dominguez Channel / Los Angeles and Long Beach Inner Harbor Watershed; and,
• The Los Cerritos Channel / Alamitos Bay Watershed.

The revised – and now approved – CII Permit documents are available on the Board’s CII Stormwater Program webpage at:

https://www.waterboards.ca.gov/losangeles/water_issues/programs/stormwater/Commercial_Industrial_and_Institutional/index.html

BACKGROUND:

The LA Regional stormwater permit focusing on commercial, industrial and institutional (i.e., private schools, private hospitals) property stormwater discharges has been a top policy priority for NAIOP SoCal for nearly two years. For those unfamiliar with this permit, Board staff has been working over the course of several years on a permit that would regulate all stormwater dischargers from all CII properties in the two aforementioned Los Angeles regional watersheds:

Any business / person that owns a shopping center, parking lot, business center, and other commercial or industrial property with 5 acres or more of impervious surfaces (impervious surfaces include rooftops) would now need to develop a stormwater pollution prevention plan, conduct the sampling of stormwater runoff, and either install costly mitigation measures or participate in a regional watershed program in order to comply with the permit.

The following images will help to put into perspective the geographic scope of the CII Permit and to help you determine if you may have qualifying property in the two targeted LA Regional watersheds:

During the hearing, businesses and property owners continued to raise concerns with the permit and requested that the Board defer a vote in order to provide staff with the opportunity to meet with stakeholders to address as many remaining concerns as possible. On the other hand, environmental organizations urged adoption of the permit.  

At the end of the hearing, the Board voted to approve the permit. As part of the permit approval, there are some built-in timelines that do afford property owners with time to prepare for how they will seek coverage under the new permit regime. Important dates / milestones for your awareness include:

• Effective Date of the Permit: The effective date of the permit is 100 days after adoption of the permit. This timeline would have the permit go into effect on October 3, 2026.
  
• For properties within the two watersheds that meet the impervious surfaces acreage threshold, property owners will have 12 months after the effective date to submit a Notice of Intent (NOI) and a stormwater pollution prevention plan for the property to the Regional Board.

• The sampling requirement in the permit will need to be completed within 18 months of the effective date of the permit.

• The Board approved a 3.5 year deadline from the effective date of the permit for permittees to select a compliance option and begin compliance obligations. The Board also directed staff to schedule a 2.5 year check-in with the watershed management groups to hear from and assess their progress in establishing the necessary legal frameworks and agreements to enable permittees to opt in to Compliance Option #1.

During the hearing, NAIOP SoCal provided comments on the permit and highlighted several issues of concern including who was actually notified by the Board staff regarding this new permit in the two watersheds and the interplay between the fee associated with this new permit and the increase in property tax throughout Los Angeles County approved by voters to help pay for stormwater runoff projects.  

We informed Board members regarding our multiple requests for any lists used to identify and contact property owners. During the hearing, the Board Chair acknowledged that staff should have provided NAIOP SoCal with such a list and instructed staff during the hearing to carry out this request. We continue to await receipt of the list.

NAIOP SoCal also requested information for property owners to understand better the dynamic between the fee our Members would be paying as part of the CII Permit and the increased property tax assessment in Los Angeles County to pay for projects to improve stormwater issues. We argued that those commercial and industrial property owners in the two watersheds are being double-taxed based on the location of their property – versus other areas in the county – to pay for stormwater projects. At a minimum, we suggested that commercial and industrial property owners should receive credit for the amount of money already generated by the stormwater property tax, to date, and in the future.

Now that the CII Permit has been formally approved, any property owner or stakeholder group/association seeking to challenge the adoption of the permit has a 30-day window of time after the effective date of the regional Board’s action to file a formal appeal with the State Water Resources Control Board. At this juncture, it is unclear if anyone plans to appeal the adoption of the CII Permit.

For further information on the LA Regional Water Board’s CII stormwater permit, please reach out to Mihran Toumajan (mtoumajan@naiopsocal.org / 714.550.0309).



[1]  In June 2026, the California Coastkeeper Alliance petitioned six of the state’s other eight regional water boards to initiate development of CII stormwater permits for selected watersheds. NAIOP SoCal is reviewing those petitions against the recently approved Los Angeles Regional CII Permit, whose compliance framework could become the baseline for similar regional requirements, and reinforce the establishment of a statewide stormwater permit applicable to qualifying CII properties.