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US Fish & Wildlife Service FieldNotes

PACIFIC SOUTHWEST REGION: National Fish Passage and Anadromous Fish Restoration Programs work with partners to improve the Calaveras River for fish, water and people

Region 8, November 15, 2013
Caprini low-flow crossing on the Calaveras River in March 2010.
Caprini low-flow crossing on the Calaveras River in March 2010. - Photo Credit: n/a
The Caprini crossing in October 2013
The Caprini crossing in October 2013 - Photo Credit: n/a
Top view of the Caprini crossing on the Calaveras River.
Top view of the Caprini crossing on the Calaveras River. - Photo Credit: n/a
Stockton Record reporter Alex Breitler and photographer Craig Sanders discuss the Caprini crossing project on-site with USFWS biologist Donnie Ratcliff.
Stockton Record reporter Alex Breitler and photographer Craig Sanders discuss the Caprini crossing project on-site with USFWS biologist Donnie Ratcliff. - Photo Credit: n/a

 

By Donnie Ratcliff

The lower portions of the Calaveras River include a complicated series of close to 100 barriers identified as potentially blocking the passage of various aquatic species, including salmon. A 2005 report by the California Department of Water Resources (DWR) identified over 35 of those barriers as high priority and the most limiting to migratory fish. In spite of the large number of barriers, the Calaveras continues to see a return of steelhead and Chinook salmon almost every year. That prompted an interdisciplinary group of experts from U.S Fish and Wildlife Service (Service), California Department of Wildlife, FishBio, Fishery Foundation and others to form the Calaveras River Fish Group. The group then began work with DWR to identify the four highest priority barriers for repair or removal on the Calaveras River.

Following the successful completion of the Budiselich flashboard dam fish passage project in 2011, project partners set their sights on the next highest priority barrier. That turned out to be the Caprini low-flow crossing, which was originally built decades ago by the current landowner’s grandfather to facilitate access for agricultural equipment to family property located on both sides of the river. The historical crossing consisted of three small culverts embedded in a large concrete slab which created fish passage problems at all but the very highest flows. Due to a height gap between the culvert barrier and river level at low river flows fish were not able to make the leap into the culvert to continue upstream.  Likewise, at moderate flows the rushing waters velocity made it difficult for fish to swim through the culvert.

The Caprini project began with an assessment of the general needs and goals of all involved parties so that the final project at the site would provide maximum benefit and function to all stakeholders. The final design for a new fish passage consisted of six modular pre-cast concrete box culverts placed in three rows, each two boxes wide, which ultimately functions as a bridge. The current design allows for an increase in vehicle access throughout the year, a decrease in annual maintenance by the Stockton East Water District (SEWD) and unimpeded passage for all life stages and species of fish expected to occur at the site.

The project was primarily funded by the Service’s National Fish Passage and Anadromous Fish Restoration Programs and SEWD. Additional funding and project design was provided by DWR’s Fish Passage Improvement Program. The project was implemented by SEWD with technical assistance from DWR’s Fish Passage Improvement Program. Conceptual designs and permitting activities for the final two identified priority projects are under development and project partners are actively seeking implementation funding. The collaborative efforts of all project partners related to the identification and completion of fish passage barrier projects on the Calaveras River has created a strong and effective team which plans to continue efforts well beyond the conclusion of the initial phase of barrier remediation.

Donnie Ratcliff is a fisheries biologst with the U.S. Fish and Widlife Service's Anadromous Fish Restoration Program.

 

 

 

Contact Info: Steve Martarano, 916-930-5643, steve_martarano@fws.gov