J. M. Pike Park, Protecting and Collecting Water for Modesto's Future

The City of Modesto, California had a problem: 17.3 million gallons per year of stormwater flows in its Emerald Sewer Trunk Line meant potential big-ticket upgrades to both the Trunk and the City's Sutter Avenue Wastewater Treatment Plant. But the City saw an opportunity for a better approach. Like many arid parts of the Country, Modesto has been looking for ways to capture and reuse wet weather runoff, given periods of sometimes extended drought and increased demand on both surface and overdrafted groundwater. The City's bright idea was an ambitious new $30 million dollar capture, treatment, and groundwater recharge system at its 6-acre J. M. Pike Park. The project, currently in construction, is the largest of four sites being re-imagined in order to remove stormwater cross connections to the sanitary sewer and non-functioning dry-wells that have historically contributed to significant wet weather flows to the Plant, avoiding future costly capital improvements to the Plant and reducing localized neighborhood flooding, while refreshing the Park. The Project's objectives are being achieved through the construction of 11,700 feet of new storm drain collection, designed to convey stormwater from 9 cross connections and 36 rock wells to JM Pike Park (Park). A subterranean retention system located under the Park will hold 21.3 acre-feet of runoff from over 100 acres and infiltrate into the underlying soils within 24 hours. Stormwater will be pre-treated in two locations to remove trash, sediment, oils, greases, and other substances prior to entering the retention system. While the Park has recently upgraded play areas, this project provides an extensive rehabilitation to improve operations and maintenance, accessibility, and aesthetics. Existing turf and irrigation systems are being replaced with more water efficient turf varieties and drought tolerant trees and plantings. The irrigation system for trees is being separated from turf irrigation to allow turf to dry while trees remain watered, which enhances conservation during droughts. Rain gardens are being constructed to capture and treat runoff from the impervious surfaces in the Park. New walking paths, lighting and seating are being added, and all facilities are being reconstructed to satisfy the Americans with Disabilities Act (ADA). The City is also capitalizing on the construction within its rights-of-way to replace 23,500 feet of under-sized, low-pressure water mains in neighborhoods around the Park. Existing steel pipes are being replaced with PVC mains and relocated from alleys into public rights-of-way to facilitate future access and maintenance, improve system reliability, flows, and pressures. Fire hydrants, meters, and system appurtenances are also being replaced to City standards. This project's design is complete, and construction is expected to be complete by October of 2024. The Park's reimagining represents a true multi-objective stormwater capture and re-use project: eliminating wet weather flows to the Plant, reducing neighborhood flooding, enhancing public recreational space, improving the resiliency of the public water supply and making public rights-of-way more accessible to the Community. This presentation will highlight a successful approach for reducing wet weather flows at scale. The audience will benefit from learning about the development and implementation of one of the largest public projects of its kind. The presenters will focus on sharing design and construction lessons learned, as well as the City's strategy to leverage available funding to achieve broad public benefits to the local community, including funding and partnership strategies that can help communities across the nation remove roadblocks to cost saving implementation. Audience participation will be encouraged through engaging question and answer periods throughout the presentation, allowing for discussion of specific challenges and opportunities of these types of projects.