NEWS WORTH NOTING: Subsidence Lowers Friant – Kern Canal by 5 Inches in 5 Months; Juvenile Central Valley spring-run chinook salmon monitoring; California Central Valley steelhead monitoring plan

Subsidence Lowers Friant – Kern Canal by 5 Inches in 5 Months

From the Friant Water Authority:

When officials with the Friant Water Authority (FWA) did an initial survey in April 2017 to measure subsidence along the Friant-Kern Canal, they expected to see impacts from the recent drought. What they measured in some places was a nearly three foot drop in the canal elevation.

Even with last winter’s record breaking rain, snowfall and runoff, they assumed the discouraging trend would continue. What they found in early August when they resurveyed portions of the canal confirmed their fears. Since April the canal has dropped another 5 inches in one particularly hard hit location.

“These findings are not entirely unexpected,” commented Doug DeFlitch, Chief Operating Officer for FWA. “Subsidence is a long-term challenge for the Friant Division, and will not be remedied after one year of good rain.”

Jason Phillips, Chief Executive Officer for FWA added, “The continuing subsidence issue is why FWA is exploring possible funding mechanisms for bringing the Friant-Kern Canal back to its designed operational potential. A fully functioning canal will help achieve the groundwater/surface water balance the Friant-Kern Canal was designed to maintain, and lessen the impacts of subsidence.”

Land subsidence is the gradual sinking of an area of land which occurs more dramatically in the region when groundwater is over drafted. Water that is removed from very fine clay-like pore space in the subsurface no longer has its internal strength and over time compresses and the surface of the land drops. During the drought when surface water supplies were limited or unavailable, regional farmers, cities and others relying on surface water supplies turned to groundwater. The resulting subsidence forced cuts in water deliveries to parts of the canal system during critical times this past summer.

The Friant Division was designed to bring stability to the San Joaquin Valley’s groundwater supply, which was threatened at the beginning of the 1920s by decades of groundwater pumping. The Friant Division’s two canals – the Friant-Kern and the Madera – source high-quality surface water from the San Joaquin River that supports crops, cities, and groundwater recharge. This investment to establish the Friant Division has paid off by providing stable surface and groundwater supplies that created and sustain a world-class agricultural sector that in turn supports numerous communities and businesses.

The Friant-Kern Canal is a gravity-fed facility and currently does not rely on pumps to move water. Subsidence disrupts the natural grade line, which negatively affects the canal’s ability to convey water. As the surface expression of land subsidence continues to occur, the canal will continue to lose capacity. Current estimates put those reductions at nearly 60% of design.

FWA is a joint-powers authority formed in 2004 by a majority of the water agencies receiving water from the Friant Division of the Central Valley Project. Its primary purposes are to operate and maintain the Friant-Kern Canal and to serve the information and representation needs of its member agencies.

For more information, click here.

Juvenile Central Valley Spring-Run Chinook Salmon Monitoring

December 1, 2017 – June 1, 2018

The Bureau of Reclamation and California Department of Fish and Wildlife, as part of the San Joaquin River Restoration Program (SJRRP), will perform monitoring for juvenile spring-run Chinook salmon (Oncorhynchus tschawytscha) in Reaches 1–2 of the Restoration Area December 1, 2017 – June 1, 2018.

This effort will estimate production and distinguish strategies for juvenile Chinook Salmon emigration from the Restoration Area, overall survival rates for each juvenile life stage in rearing and migration areas, the spatial distribution of mortality and, if feasible, determine behavioral responses of juvenile emigrants to flow management strategies (e.g., pulse flows). Data collected for this study will inform SJRRP fisheries and flow management decisions and habitat rehabilitation efforts that aim to increase Chinook salmon abundance by reducing juvenile losses in a highly modified river system.

Rotary screw traps (RSTs) are commonly used to monitor impacts of river management (e.g. habitat restoration, flow manipulation, dam management) on wild stocks. These traps can also be used to assess production and survival between life stages, such as egg-to-fry, egg-to-smolt or parr-to-smolt, and the effects of environmental parameters on migration timing and development.

Rotary screw traps (2.4-m diameter cone) will be operated at four locations (December–June) to index survival between the locations and estimate the size and life stage of juvenile Chinook salmon emigrating from the spawning and rearing locations upstream of Mendota Pool.

For more information about this activity, please visit

For more information about the San Joaquin River Restoration Program, please visit or contact Josh Newcom, Public Affairs Specialist, at 916-978-5508 or

California Central Valley Steelhead Monitoring Plan

December 1, 2017 – April 30, 2018

The Bureau of Reclamation (Reclamation), as part of the San Joaquin River Restoration Program (SJRRP), will perform a monitoring effort to identify presence/absence of adult California Central Valley (CCV) steelhead (Oncorhynchus mykiss) in the upper San Joaquin River (SJR) and its adjacent sloughs.  CCV steelhead are believed to be extirpated from all waters upstream of the Merced-SJR confluence. However, Restoration Flows have reconnected historically desiccated river sections, and these flows could attract adult steelhead into the Restoration Area from December 2017 through April 2018. Adult steelhead accessing the SJR upstream of the Merced River confluence could be exposed to loss into sloughs and would not have access to appropriate spawning habitat due to a number of impassable barriers. As a result, Reclamation has implemented a steelhead monitoring and detection plan (SMP) for the SJR upstream of the Merced River confluence that would, in the event of a capture, document and transport the fish to suitable habitats downstream of the mouth of the Merced River.

CCV Steelhead Monitoring Plan is an important SJRRP study to ensure its commitment to restore and maintain fish populations within the Restoration Area. No CCV steelhead were detected or captured during past sampling periods.

However, Restoration Flows could attract adult steelhead into the Restoration Area, particularly if the flows are higher than those in the other SJR tributaries. While steelhead abundance and distribution in the SJR Basin have substantially decreased, and steelhead were extirpated from the Restoration Area following construction of Friant Dam, more favorable winter and spring water conditions may attract steelhead strays from other tributaries.  Reclamation has proposed the SMP to facilitate detection of steelhead on the SJR upstream of the Merced River confluence and subsequent trapping and transport to suitable habitats downstream of the Merced River confluence.

Migrating adult steelhead are difficult to monitor using techniques commonly used (e.g., carcass surveys, snorkel surveys, redd counts) to assess salmon populations due to their unique life-history traits. Steelhead, unlike salmon, may not die after spawning. Therefore, carcasses may not be available for surveys. In addition, steelhead migrate and spawn during the late-fall, winter, and spring months when rivers have periods of pulse flows, high flows (e.g., flood releases), and higher water turbidities which may make conditions unsuitable for monitoring using these methods.

Steelhead monitoring activities are proposed for the area below Mendota Dam, or to the uppermost contiguous wetted section of the SJR, from the confluence with the Merced River including adjoining sloughs.  During 2011–2014 surveys, the confluence of the Eastside Bypass with the SJR was considered the furthest upstream extent for CCV steelhead migration because of low water conditions and impassable upstream barriers.  Additional sampling may occur upstream of this area in the event conditions allow for fish passage past the Eastside Bypass Control Structure and Sack Dam upstream to Mendota Dam.

Steelhead monitoring activities will occur from December 1, 2017 – April 30, 2018  for two continuous weeks each of the four months in the Restoration Area.

Access to the locations will occur from the public right-of-way or in areas where private landowners have granted access.

For more information about this activity, please visit

For more information about the San Joaquin River Restoration Program, please visit or contact Josh Newcom, Public Affairs Specialist, at 916-978-5508 or

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About News Worth Noting:  News Worth Noting is a collection of press releases, media statements, and other materials produced by federal, state, and local government agencies, water agencies, and academic institutions, as well as non-profit and advocacy organizations.  News Worth Noting also includes relevant legislator statements and environmental policy and legal analyses that are publicly released by law firms.  If your agency or organization has an item you would like included here, please email it to Maven.

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