What We Oppose - Geomorphological Engineering and Creek Rechanneling

We view the creek as a natural ecosystem that should largely be left to its own devices. We are opposed to the unproven and radical method of Creek channel narrowing and relocation using heavy equipment and imported fill as was performed in the Winters Putah Creek Park project. In the process of this work, acres of native trees and vegetation were removed; habitat for mammals, fish, birds, and reptiles was destroyed; and soil was severely compacted, compromising its ability to allow replants to survive nd sustain growth of the native plant community.

This radical Creek bed transformation is known as “geomorphological engineering”. Proponents claim that it will result in a larger and healthier riparian floodplain with increased native plant and animal habitat and a new streambed sized to accommodate the reduced water flow released from Monticello Dam. Supporters of this technique also claim it will result in cooler water temperatures, beneficially impacting salmon spawning and trout habitat, and will enhance vegetation to improve bird habitat.

What has been observed, however,  is that the imported heavy clayey compacted fill material has been unable to support most of the replanted native vegetation because the indurated fill impedes water percolation, air infiltration, and root growth in the floodplain. Some mature trees that were not bulldozed on the periphery of the graded soil are now also dying due to water deprivation because lateral movement of water through the compacted fill does not occur.

The heavily engineered and compacted floodplain and streambed also covered and eliminated generations of seed bank stock in the original floodplain, and severely reduces the groundwater recharge needed to replenish local water tables. There has been no scientific study of this impact.

Prior restoration projects on Putah Creek have improved human access to the creek and added gravel for salmon spawning, but theWinters Putah Creek Parkway project removed ponds that were occupied by other fish species, waterfowl, amphibians, beaver, otter, and the endangered Western Pond Turtle.

Now, plans are underway to apply the same destructive approach to the entire reach of Lower Putah Creek. At a cost of about $100,000, a Programmatic Enviromental Impact Report (PEIR) has been written to provide the foundation for the multi-million dollar Lower Putah Creek Restoration Project, which proposes to “restore and enhance geomorphic and ecological function” on over 24 miles of Putah Creek between the diversion dam and the Yolo Bypass Wildlife Area.  We have challenged that  PEIR in court as insufficiently addressing the failures seen in the Winters Putah Creek Park.

What We Support – Creek Preservation, Constructive Restoration, and Enhancement

1.  Invasive Species Removal and Native Replanting – Removal of invasive plants that inhibit and choke out native flora and replace with native plantings.

2.  Trash Removal – Periodic collection of accumulated trash improves animal life and human recreation and enjoyment of the Creek’s beauty.

3.  Trail Maintenance – Repair of existing trails and selective development of new trails on public lands to allow access to the Creek.

4.  Public Education and Volunteer Engagement - Collaboration with other Creek stewards, including other non-profit organizations, the cities of Davis and Winters, Solano and Yolo Counties, landowners and continued engagement of public volunteers.

5.  Improvement of Existing Salmonid Habitat - Support enhancement of existing riffles for spawning habitat.

6.  Maintaining and Monitor Flow Regime - Support maintaining the cornerstone 2000 Accord with the Solano County Water Agency to ensure water releases that will maintain and enhance native fish populations, including salmon and trout, while also providing for the agricultural needs of adjacent property owners.