SB 601 amends the California Water Code to treat many non‑navigable waters — labeled “nexus waters” — as waters of the state for permitting, monitoring, reporting, and enforcement purposes. The bill directs the State and regional water boards to include nexus waters in Clean Water Act processes (like the Integrated Report and TMDLs), requires reporting and prohibitions for discharges to those waters, and mandates that waste discharge requirements for point source discharges to nexus waters meet federal standards.
The measure also creates a mechanism to annually adjust civil monetary penalties for a set of water violations beginning January 1, 2026, establishes a Penalty Adjustment Account to receive those funds, and expands the set of public prosecutors and agencies that may enforce nexus‑water requirements — including a civil penalty ceiling of $75,000 per day per violation in court actions. Collectively, these changes broaden the regulatory footprint on previously non‑navigable waters and raise potential compliance and enforcement exposure for dischargers and local governments.
At a Glance
What It Does
SB 601 defines “nexus waters” (many non‑navigable waters) and requires the state and regional boards to treat them like navigable waters when implementing Clean Water Act processes and issuing waste discharge requirements. It extends reporting and filing obligations to discharges into nexus waters, forbids unauthorized discharges, and requires waste discharge requirements for nexus waters to meet at least the stringency of analogous federal permits. The bill also requires the State Water Board’s executive director to apply an annual cost‑of‑living adjustment to a specified list of civil penalties and creates a Penalty Adjustment Account to receive those funds.
Who It Affects
Directly affected parties include holders of point‑source permits or discharge operations that previously fell outside federal jurisdiction (e.g., certain small industrial dischargers, landowners with constructed ponds or conveyances, and some municipal or agricultural point sources). State and regional water boards gain expanded authority and new obligations; local prosecutors and the Attorney General get clearer statutory standing for civil enforcement. Consulting engineers, labs, and remediation contractors will see increased demand for monitoring, reporting, and permit work.
Why It Matters
The bill effectively restores and locks in broader state regulation of waters that federal rules may have left out after 2023, shifting regulatory risk and permitting burden to California actors. It increases enforcement teeth (higher, inflation‑indexed penalties and new civil remedies), which raises both compliance costs and litigation risk for regulated parties. For regulators and counsel, SB 601 changes which waters to watch, what permits to obtain, and how to budget for monitoring and potential liability.
More articles like this one.
A weekly email with all the latest developments on this topic.
What This Bill Actually Does
SB 601 creates a statutory category called “nexus waters” — defined as waters of the state that are not navigable waters — and enumerates a long list of exclusions (groundwater, many artificial or ephemeral conveyances, prior nonjurisdictional waters determined by EPA or the Corps before May 25, 2023, and other specific features). The bill requires that nexus waters be incorporated into the State and regional boards’ Clean Water Act processes (for example, the California Integrated Report and the development or maintenance of TMDLs) and preserves any water quality standards that applied to nexus waters as of the specified prior dates unless a more stringent standard is adopted.
For permitting and discharge control, the bill mandates that regional boards prescribe waste discharge requirements for point source discharges to nexus waters that implement relevant federal standards. Where the bill speaks to discharges from point sources to nexus waters, those waste discharge requirements must, at minimum, meet the requirements in the chapter that implements the federal Clean Water Act in state law and cannot be authorized through waivers.
The text also expands the statutory definition of “discharge” to explicitly include additions of pollutants from point sources to nexus waters and applies the existing prohibition on unauthorized discharges to those waters.SB 601 tightens reporting obligations by making reporting requirements applicable to discharges to nexus waters; it preserves the existing procedural timing for proposed discharges and for treatment works (including the 180‑day advance filing requirement for proposed discharges or commencement of operation). On enforcement, the bill adds a cause of action authorizing the Attorney General, the State Water Board, regional boards, or local public prosecutors to sue over violations related to nexus waters, allows courts to award injunctive relief and attorney’s fees to prevailing plaintiffs, and caps civil penalties recoverable in court at $75,000 per day per violation.On penalties and funding, SB 601 requires the State Water Board executive director to perform an annual inflation adjustment to a list of civil monetary penalties beginning January 1, 2026, using a Consumer Price Index‑based cost‑of‑living calculation (with a cap on year‑to‑year increases).
The bill creates a Penalty Adjustment Account within the Waste Discharge Permit Fund to receive revenues from those adjusted penalties, and directs that moneys deposited there, upon appropriation, be used to assist regional boards and public agencies in cleanup and abatement of water pollution. The bill contains severability and a ‘‘more stringent provision prevails’’ clause to preserve existing stronger protections.
The Five Things You Need to Know
SB 601 defines “nexus waters” as waters of the state that are not navigable waters, but excludes features such as groundwater, prior EPA/Corps nonjurisdictional waters determined before May 25, 2023, and many artificial or ephemeral conveyances.
Beginning January 1, 2026, the State Water Board’s executive director must annually adjust a specified set of civil penalties by a Consumer Price Index‑based cost‑of‑living calculation, subject to rounding and a year‑to‑year cap.
Waste discharge requirements for point source discharges into nexus waters must implement relevant federal standards and be at least as stringent as analogous Clean Water Act permits; waivers cannot authorize those discharges.
The bill expands enforcement standing: the Attorney General, the State Water Board, regional boards, and local prosecutors may bring civil actions related to nexus waters, and courts may impose civil penalties up to $75,000 per day per violation.
SB 601 requires reporting for discharges to nexus waters and preserves existing procedural timing (including the 180‑day advance filing for proposed discharges or operation of treatment works) except where the state board or a regional board requires otherwise.
Section-by-Section Breakdown
Every bill we cover gets an analysis of its key sections.
Definition of 'nexus waters' and 'federal standards'
Adds a new definition section that (1) defines “federal standards” as laws and regulations implementing the Clean Water Act in effect as of January 19, 2025 (with later, more stringent federal changes to apply), and (2) defines “nexus waters” as waters of the state that are not navigable waters, followed by a detailed list of exclusions (groundwater, prior nonjurisdictional waters determined before May 25, 2023, treatment ponds, many artificial features, swales, etc.). Practically, this is the map: it tells regulators and regulated entities which non‑navigable features the state intends to bring under permitting and which features remain outside state oversight under this bill.
Inclusion of nexus waters in CWA processes and Integrated Report
Requires both the State Water Board and regional boards to include nexus waters in Clean Water Act (33 U.S.C. §1313(d)) processes such as the California Integrated Report and the development or maintenance of TMDLs. The section preserves listings and TMDLs that were in place or in development for nexus waters prior to the bill’s cutoff dates, ensuring continuity of existing regulatory actions while directing boards to fold nexus waters into routine CWA planning work.
State board authority to adopt plans for nexus waters
Amends the state board’s plan‑adoption authority to allow water quality control plans to be adopted for waters where water quality standards are required by the Clean Water Act and explicitly for nexus waters. Adopted plans supersede regional plans to the extent of any conflict, centralizing the ability to set state‑level objectives for waters now labeled as nexus waters.
Permit requirements: implement federal standards for discharges to nexus waters
Modifies regional board permit prescription language so that, for discharges from point sources to nexus waters, the board must implement relevant federal standards; where conflicts exist, provisions implementing the federal statute control. The amendment shifts the baseline for effluent and permit limits for those discharges toward federal CWA requirements, narrowing the discretionary scope regional boards historically had under Section 13241 for these specific discharges.
Reporting and prohibition extended to nexus waters
Expands the existing reporting and prohibition framework so that persons who discharge, propose to discharge, or operate treatment works that affect nexus waters must file the same reports required for discharges to navigable waters. It retains the advance‑filing and 180‑day timing requirements for proposed discharges or commencement of operation, while carving out that reports are not required where the state board or regional board decides otherwise (subject to the bill’s broader inclusion of nexus waters).
Waste discharge requirements for nexus waters must match federal stringency
Creates an explicit standard of comparison: waste discharge requirements for nexus waters must implement limitations at least as stringent as analogous federal permits and ensure compliance with specific CWA sections (as they existed before May 25, 2023). The section bars authorization of discharges to nexus waters via waivers and instructs that dredged or fill discharges to wetland nexus waters follow the state's wetland policy, establishing both substantive and procedural guardrails.
Annual penalty adjustments and expanded civil enforcement
Section 13352 requires the executive director of the State Water Board to perform annual cost‑of‑living adjustments to a specified list of civil penalties (with rounding rules and a maximum percentage increase), creates the Penalty Adjustment Account in the Waste Discharge Permit Fund to hold those revenues, and specifies their use for cleanup and abatement upon appropriation. Section 13385.5 authorizes the Attorney General, the State Water Board, regional boards, and local prosecutors to bring civil actions related to nexus waters, authorizes injunctive relief, fee awards to prevailing plaintiffs, and sets a court‑imposed penalty ceiling of $75,000 per day per violation.
This bill is one of many.
Codify tracks hundreds of bills on Environment across all five countries.
Explore Environment in Codify Search →Who Benefits and Who Bears the Cost
Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- Downstream communities and water users — they gain broader statutory coverage for smaller streams, wetlands, and other non‑navigable features, which can translate into stronger protection of drinking water sources, fisheries, and local recreation areas.
- State and regional water boards — they get clearer statutory authority to regulate a wider set of waters, plus a funding mechanism (Penalty Adjustment Account) that, if funded by appropriations, targets collected penalties back to cleanup and abatement work.
- Environmental and public‑health advocates — the bill gives them clearer legal footing to push for listing, TMDLs, and enforcement actions on waters that were previously outside federal jurisdiction.
- Remediation and environmental services firms — expanded monitoring, permitting, and cleanup obligations will increase demand for compliance consulting, laboratory services, and remedial contracting.
Who Bears the Cost
- Owners/operators of point sources previously outside federal permits (small industrial sites, certain agricultural conveyances, pond operators) — they face new permitting responsibilities, monitoring and reporting costs, and potential exposure to higher and inflation‑adjusted penalties.
- Municipalities and local governments — stormwater dischargers, some treatment works, and public works projects may need new filings, tighter controls, and additional capital or O&M spending to meet waste discharge requirements applicable to nexus waters.
- Regulated industries with stormwater or minor discharges — those that relied on narrower federal jurisdiction may incur legal, engineering, and transactional costs to obtain permits or to retrofit controls.
- Regional boards and state agencies — while gaining authority, they will also face increased administrative workload for listing, permitting, inspections, and enforcement without a guaranteed corresponding funding increase.
Key Issues
The Core Tension
The central dilemma of SB 601 is balancing stronger water quality protection against regulatory certainty and cost: the state asserts broad authority to protect non‑navigable waters (protecting public and environmental health) but, in doing so, imposes new permitting, monitoring, and liability risks on owners and operators who relied on narrower federal jurisdiction, while creating significant administrative and litigation challenges for regulators and courts.
SB 601 is aggressive in scope but leaves several implementation and legal questions unresolved. The bill leans on a hybrid of state and federal standards: it ties waste discharge requirements for nexus waters to federal statutes and to federal standards ‘‘in effect as of’’ a cited date, while also preserving older state listings and TMDLs.
That creates potential tension over which specific federal metrics apply when federal rules change, how quickly regional boards must modify permits to track federal updates, and whether courts will accept the statute’s instruction to ‘‘treat’’ nexus waters as if they were federally navigable waters when federal jurisdiction remains in dispute.
The bill contains drafting inconsistencies and multiple date references (for example, references to January 19, 2025 and May 24, 2023 in relation to which standards and listings persist), which may generate interpretive disputes at the outset of implementation. Practically, regulated parties will challenge both the scope of ‘‘nexus waters’’ (is this ditch, pond, or swale covered?) and whether the state can impose CWA‑equivalent permitting obligations where federal agencies previously declined jurisdiction.
Those litigation risks will raise uncertainty about permit timelines and compliance expectations. Separately, the annual penalty adjustments add predictability in methodology but also a political and fiscal challenge: increased penalties shift cleanup costs onto permittees while relying on the Legislature to appropriate collected funds back into remedial programs, which is never guaranteed.
Finally, the bill expands enforcement tools for public prosecutors and agencies, including fee awards and a high statutory damages ceiling. That empowers local enforcement but produces uneven consequences: well‑resourced plaintiffs may litigate aggressively, producing case law and administrative precedent that could either clarify or further complicate compliance.
The administrative burden on boards to process new permits, make jurisdictional determinations, and maintain monitoring programs is real — the bill does not contain commensurate, guaranteed funding for those front‑end costs, so implementation could slow or shift costs to regulated entities through fees and enforcement settlements.
Try it yourself.
Ask a question in plain English, or pick a topic below. Results in seconds.