Gilbert, Arizona’s North Water Treatment Plant (NWTP) expansion and reconstruction project has reached 75% completion, with the town reporting that the largest capital improvement project in its history remains on schedule and within its approved budget.

Construction began in March 2022, with final completion expected by winter 2028. The facility serves as the primary drinking water source for most of Gilbert’s residents and supports commercial districts. At full build-out, the expanded plant is expected to provide more than 70% of the town’s total water supply.

The next major milestone is the planned startup of the new water treatment process in spring 2027, ahead of the project’s final completion. Remaining work includes completing a granular activated carbon (GAC) facility to improve the plant’s ability to remove unwanted substances from drinking water, rehabilitating treatment processes that will remain in service, demolishing unused systems and restoring the site.

The project is being delivered through phased Guaranteed Maximum Price (GMP) packages. Gilbert said the final packages are planned and remain within the project budget, with their scope and costs being finalized. The packages are expected to go before the Town Council within the next 12 months.