The water world is filled with interesting terminology – excess water, firming, intentionally created surplus – to name a few. And then there’s wheeling, which doesn’t have anything to do with wheels at all!

Wheeling refers to the use of critical infrastructure – in our case, the Central Arizona Project (CAP) aqueduct – to transport water other than CAP’s normal Colorado River supply. This water is referred to as non-Project water.

At the outset, that seems like a very simple concept. Must be a simple thing to do, right?

As with virtually everything in the aforementioned water world, it’s anything but simple. In fact, although wheeling was discussed back in the early 1980s (before CAP had even delivered a drop of water) and was authorized in the 1988 Master Repayment contract between the Central Arizona Water Conservation District (CAWCD) and the Bureau of Reclamation (Reclamation), water has yet to be wheeled through the CAP system.

But we’re actually getting close thanks in part a Water Quality Guidance Document approved by the CAWCD Board in September 2025. This document is intended for projects that propose to introduce non-Project water directly into the CAP canal. This revised version satisfies the requirement to establish uniform water quality standards under CAP’s System Use Agreement and will allow for the re-initiation of the National Environmental Policy Act (NEPA) for wheeling projects.

This Water Quality Guidance Document was developed by CAP and  Reclamation, based on a CAWCD Water Quality Standards Task Force that met from May 2017 to February 2019. Through that public process, the Task Force incorporated input from a broad range of CAP stakeholders and interested parties. The effort led to the adoption of a consensus proposal with strict water quality standards that are highly protective of the CAP water supply.

Now that this document has been approved by both CAWCD and Reclamation, CAP is one step closer to “wheeling without wheels!”