Department of Water Resources Home

Environmental Services


sutter bypass

Environmental Services

Dean Messer, Chief

3500 Industrial Blvd.
West Sacramento, CA 95691
(916) 376-9699

Mailing Address:
P.O. Box 942836
Sacramento, CA 94236-0001



Stanislause River Riffles

Merced River Salmon Habitat Enhancement Project - Phase II (Ratzlaff Reach)


Merced River Salmon Habitat Enhancement Project - Phase II (Ratzlaff Reach)


This phase of the project is located on the Merced River between river miles 40.0 and 40.5, approximately 6 miles southwest of the town of Snelling. It was Phase II (Ratzlaff Reach) of the Merced River Salmon Habitat Enhancement Project (MRSHEP), but the first construction phase.

Failure of berms in the reach had allowed the river to flow through an abandoned gravel pit. The river abandoned a channel that was already heavily constricted and overgrown with vegetation. The berms had limited the river width to fifty feet in some areas before it failed.

ratzlaff location

Current Status

Actual construction was started in June of 1999 and was completed in October of the same year. A 300 foot wide floodway was created with a berm to isolate the river from the pond. Of the original 46 acres of the project pond (including the small channel remnant), the floodway and berm eliminated about 20 acres and isolated an area of about 26 acres. Approximately 460,000 tons of fill material was used to construct the project.


The project is subject to monitoring as scheduled in the plan. Baseline data were taken at completion of construction, and subsequent monitoring is being done to enable comparisons between as-built and current conditions. Monitoring actions include cross sectional surveys, water surface elevation surveys, pebble counts, bulk samples, and tracer gravel. This data is used to determine hydraulic characteristics, sediment transport and other morphology of the project.


The engineering report for this project goes into greater detail about the project and the design used. The engineering report and the 2001 monitoring report can be found in the Publications section of this website.

Additional Photos

post const

Animated GIF of Project Site Before and After Construction.


Arial Photo of Project Spring 2002.


Downstream End of Project, Spring 2000.


Downstream End of Project, Spring 2002.