Surface Water Protection

Protected Surface Waters List | Surface Water Protection

What is the Protected Surface Waters List?

The Protected Surface Waters List, or PSWL, is a list of waters regulated either under the Clean Water Act (CWA) or the Arizona Surface Water Protection Program (SWPP). If a water meets the federal Clean Water Act definition of a Waters of the United States (WOTUS), it is automatically included on the PSWL and regulated as a federally protected water. Waters deemed not to be a WOTUS under the current federal definition, may be regulated through SWPP if that water meets the definition of a state protected surface water in Arizona Revised Statutes (A.R.S) §49-221(G) | View >

What is the Initial PSWL?

During the 2021 legislative session, the Arizona legislature approved the creation of the SWPP in House Bill 2691. The effective date of the SWPP was Sept. 29, 2021, and required an Initial PSWL to be published in the Arizona Administrative Register (AAR) within 30 days. This list was published on Oct. 29, 2021 | View PSWL List (27 AAR 2538) > | View PSWL eMap >

The Initial PSWL will be replaced by a Final PSWL required to be published by Dec. 31, 2021, as part of the SWPP rulemaking | Learn More >

How was the Initial PSWL created?

To create the Initial PSWL, ADEQ evaluated waters for WOTUS status on Appendix B of Title 18, Chapter 11, Article 1 | View>

Historically, Appendix B was designed to align with federal requirements for Arizona’s CWA programs. The evaluation of Appendix B waters was conducted to ensure that protected waters aligned with the pre-2015 WOTUS definition that became effective on Aug. 30, 2021 when a federal judge vacated the Navigable Waters Protection Rule (NWPR). When the NWPR was vacated, the U.S. Environmental Protection Agency (EPA) released guidance for states to return to the pre-2015 WOTUS definition.

Over the month following the vacatur of the NWPR, ADEQ staff reviewed all Appendix B waters for WOTUS status based on the pre-2015 guidance. The following logic was applied:

  • If a water was evaluated as WOTUS, it was listed on the PSWL as required in A.R.S. §49-221(G)(1). Note: State-level legislation cannot change the scope of a federal program that is implemented in Arizona.
  • If a water was evaluated and there was definitive evidence it did not connect to a Traditionally Navigable Water (TNW), the water was classified as non-WOTUS and evaluated for inclusion on the PSWL as a state protected water as defined by A.R.S §49-221(G)(1). If a non-WOTUS water met the definition of a state protected water, it was included on the PSWL.
  • If a water was evaluated and there was not sufficient clarity in the connectivity or lack thereof to a TNW, ADEQ chose to regulate the water under existing Appendix B standards until new or additional data, information and/or processes could yield a definitive classification.

Only those waters that have been historically regulated as WOTUS on Appendix B, were evaluated for inclusion on the PSWL.

What if I believe a water currently being regulated as WOTUS is not WOTUS or vice versa?

ADEQ recognizes there is a decades long debate around what is and is not a WOTUS and that additional clarity, data, information and processes may be needed to fully evaluate some waters. The preliminary jurisdictional evaluations in the PSWL are subject to ongoing review from both ADEQ and our federal partners at the EPA and the U.S. Corps of Engineers (Corps). ADEQ will continue to engage with the federal government to ensure jurisdictional decisions are clarified for Arizona stakeholders.

Additionally, a Final PSWL is required to be published by Dec. 31, 2021, as part of the SWPP rulemaking. Stakeholders will have an opportunity to comment on the Initial PSWL during this time. The agency requests that if you have questions and/or data or information regarding a specific water to please reach out to ADEQ | Email >

ADEQ is also planning on publishing a white paper prior to formal rulemaking to gather stakeholder input regarding application of significant nexus under the pre-2015 federal regulatory regime. In addition to reviewing stakeholder input, ADEQ will work with the EPA and the Corps to better understand how significant nexus can be applied for greater regulatory clarity | Learn More >