Like any company you’d find in a community, the Conco Companies provide essential products and services to keep the city running smoothly. At the same time, the nature of Conco’s concrete services pushes us to parts of the city that aren’t typically seen by the general public. Our corporate yard is one such “hidden” area, located in an unincorporated part of Contra Costa County near Martinez, CA. It is zoned as an industrial property and thus is surrounded by similar businesses, including a refinery, sewage treatment plant, and a dump site.

Near Conco’s corporate yard lies the Walnut Creek channel, the outlet for the largest watershed in Contra Costa County.

Many of the streams and creeks that feed Walnut Creek originate from Mount Diablo and the San Ramon Valley, traveling northward before flowing out to the San Francisco Bay via Suisun Bay.  Although the channel traverses through industrial property, the creek provides a rich habitat for various species of native plants and wildlife found only in marshes and wetlands. Because the Walnut Creek channel and Suisun Bay lie amidst heavy industry businesses, few have the opportunity to truly appreciate the nature gracing this part of the watershed.

An underlying issue of the Walnut Creek channel is its ability to convey water through to Suisun Bay.

Over the years, the Walnut Creek channel has been redirected because of levees that were installed to reduce flooding. Unfortunately, this had the opposite effect.  Now the restricted waterways silt up, causing more flooding. 

Fortunately, an ambitious project will reduce flooding potential while enhancing the wetlands and improving access to the general public. 

Spearheaded by Paul Detjens with the Contra Costa County Flood Control and Water Conservation District, this project is a collaborative effort among government agencies including Flood Control, Contra Costa County, and East Bay Regional Parks to name a few. Nonprofits are also playing a role to make this project a success, including the John Muir Land Trust, and corporations such as the Marathon Refinery and Conco.

A major part of this project is to breach the levees at several locations, allowing tidal action to cover a much wider area. 

This will reduce the occurrence of silting up and create tidal wetlands that will attract the plants and wildlife that thrive in this environment. One such area that will be transformed is an old sand dredging import business previously operated by Lehigh Hanson. It was purchased by Marathon Refinery and generously donated to the John Muir Land Trust. After extensive work on the site managed by Contra Costa County Flood Control, the levee was breached on October 29^th, a significant milestone in the transformation of this formerly industrial site.

Further up the channel, Conco is working with the Contra Costa County Flood Control District to relocate part of another levee onto Conco property.  

By abandoning and breaching the old levee and building a new, stronger levee on Conco property, approximately 50 acres will be upgraded from poor quality seasonal wetlands to healthy fully tidal wetlands. This work is taking place over the summer and fall, and a future phase (around 2025) will make this reach accessible to the general public with plans calling for the extension of the Park District’s popular Iron Horse Trail to be built on the new levee.  

Although this restoration site is among industrial-zoned businesses, a new vision is forming: one where nature coexists with industry.

As a long-time business with deep roots in Contra Costa County, Conco is honored and proud to be an integral partner of this project that delivers improved landscape for all to enjoy.  For more information on the restoration project, visit www.lowerwalnutcreek.org.

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