West Yost routinely conducts accurate hydrologic/hydraulic
evaluations. This includes using dynamic 2-dimensional surface
flow modeling to more accurately predict results and to
graphically demonstrate solutions. Recent projects include the
Alamo Creek 2D Flood Study for the City of Vacaville, and 2D
modeling for a 4,000 acre alluvial fan flooding analysis in the
Mojave Desert for the Ivanpah Solar Facility project.
West Yost provided planning, analysis, environmental review,
permitting, design, and construction management services for the
Dry Creek WWTP Levee Relocation. This project included the
hydrologic and hydraulic analyses of Dry Creek in the vicinity of
the WWTP. The project provides 100 year protection of the
wastewater storage ponds while enhancing the flow carrying
capacity of Dry Creek in an environmentally sensitive manner.
West Yost prepared a 2-dimensional storm drainage model for a
proposed 400 MW solar power project covering 4,000 acres in
the Ivanpah Valley in the Mojave Desert in California. The
project is situated on an alluvial fan located at the base of the
Clark Mountain Range. Flood flows from the mountains are
initially confined in incised channels, but once arriving on the
alluvial fan, the flood flows are less confined and can take
random paths across the fan.
West Yost developed a Storm Drain Master Plan for VSFCD with a
focus on the evaluation, alternatives, and cost estimates for
addressing existing flooding problems. To assist in the master
planning process, West Yost developed computer models of
five watersheds within the District using the MOUSE
hydrologic/hydraulic model package, and conducted GPS and Total
Station field surveys of over 6,000 storm drain facilities. West
Yost also evaluated the feasibility of redirecting the highly
polluted first flush flows and dry weather flows from the
District’s storm drain system into the District’s sanitary sewer
system for treatment at the wastewater treatment plant, and
assisted the District in public outreach for the master
plan.
West Yost prepared a comprehensive storm drainage master plan and
$16 million CIP for the City of Vacaville (City). Services
included hydrologic and hydraulic analysis of major stream
systems using the HEC-1 and HEC-2 computer models, and piping
systems using the Storm computer model. Major on-line and
off-line detention basin facilities were modeled and sized for
integration into the overall stormwater plan. A financing and
connection fee study was also completed.
West Yost jointly prepared a Master Drainage Study (MDS) for the
City of Live Oak (City) and RD 777 (District). The goal for
preparing a joint document was to ensure that the two agencies
did not develop conflicting drainage plans. The purpose of the
study was to allow the City to grow without causing upstream
or downstream impacts to the agricultural areas or causing
increased flooding within the City. West Yost developed design
criteria for the City, developed an XP-SWMM hydraulic model,
evaluated the adequacy of existing City drainage infrastructure
and the District channel system, and analyzed four alternative
drainage plans for buildout associated with the City’s new
General Plan.
West Yost prepared a 2-dimensional storm drainage model for a
proposed 400 MW solar power project covering 4,000 acres in
the Ivanpah Valley in the Mojave Desert in California. The
project is situated on an alluvial fan located at the base of the
Clark Mountain Range. Flood flows from the mountains are
initially confined in incised channels, but once arriving on the
alluvial fan, the flood flows are less confined and can take
random paths across the fan.
Using Flo-2D modeling software, West Yost developed a
2-dimensional hydraulic model to route Alamo Creek overflows
through a residential neighborhoods for several miles and back
into Alamo Creek. Staff also prepared a FEMA LOMR application for
a portion of the floodplain.
West Yost under contract to an environmental services firm,
provided engineering design and construction period
services for converting 217 acres of rice farmland into a
wetlands and endangered giant garter snake habitat. The wetland
will rely on two water sources: agricultural delivery and an
onsite supplemental groundwater well.
Water balances were developed by WYA to determine the required
water supply for the project and to establish the optimal
capacity of the backup irrigation well.
West Yost reviewed previously prepared technical studies and
schematic-level designs of two design alternatives to handle
overland drainage in the Soscol Gateway area of Napa. Following
this review, West Yost developed an alternative drainage plan
that had an estimated cost of about $6.4 million, nearly a 50%
cost savings from the previously developed project (at about $12
million). In addition, the performance of this alternative, low
cost approach was verified as better than the performance of the
previous plan.
West Yost designed a stormwater pump station serving the Opus
Logistics Center in east Stockton. The project consists of the
construction of a below grade stormwater pump station with a
rated capacity of 44 cfs.
West Yost provided construction management/inspection under an
accelerated construction schedule for this 156 cfs storm water
pump station, which included trench style concrete wetwell,
mechanical “flexrake” trash rack, four propeller duty pumps with
low speed motors, and one low flow pump. Construction was
completed 10 weeks after breaking ground to provided the interim
stormwater pumping facilities needed to accept storm water.
West Yost provided planning, analysis, environmental review,
permitting, design, and construction management services for the
Dry Creek WWTP Levee Relocation. This project included the
hydrologic and hydraulic analyses of Dry Creek in the vicinity of
the WWTP. The project provides 100 year protection of the
wastewater storage ponds while enhancing the flow carrying
capacity of Dry Creek in an environmentally sensitive manner.
West Yost staff members routinely provide stormwater engineering
services in support of transportation projects. These services
include: hydrologic and hydraulic analyses to define drainage and
stormwater quality treatment facilities; design of pump stations
to evacuate storm runoff; and hydraulic and scour potential for
bridges and overcrossings.
