Orestimba Creek Feasibility Study - Stanislaus County

Economics Appendix – Draft Report - Orestimba Creek Feasibility Study, Stanislaus County, California – September 2012
Channel Mods Only – In order to increase the level of protection to the agricultural area,
modifications to enlarge the Orestimba Creek channel were examined. The channel
modifications would enlarge the channel flow cross-section for additional capacity. The existing
channel would be widened at several specific sites where the channel capacity is most
constricted. The goal of this alternative would be to accommodate flows up to 4,000 cfs within
the Orestimba Creek channel; flows higher than this design level would overtop the creek
channel and flow overland.
Chevron Levee Only – The plan includes a chevron levee that would specifically protect the
City of Newman by directing floodflows away from the urban area. The levee would divert
floodflows that break out of Orestimba Creek and flow overland across the alluvial fan. The
levee would be comprised of two segments. The first segment of the levee would be constructed
by raising the existing elevation of an east-west road by several feet. The second segment would
be comprised of enlarging the existing berm of an irrigation canal that runs north to south to
prevent floodflows from overtopping the canal bank and flowing in to town.
Cheveron Levee + Channel Mods – The plan would include a chevron levee constructed along
an unnamed farm road about one mile north of Stuhr Road, and improvement of the east bank of
the CCID Main Canal from the farm road south to Newman Wasteway, a distance of about four
miles. Hybrid 3 would also include increasing the capacity of Orestimba Creek from its present
minimum of 1,700 cfs to a uniform minimum capacity of 3,500 cfs.
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