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 design standards for drainage pump station
design and provided on-call consulting services to the City for
drainage master planning of the North Natomas development area.
The design standards were used by various design engineers for
the design of seven pump stations, numerous detention/water
quality basins, and conveyance systems servicing the 5,000-acre
development area.
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 prepared a comprehensive drainage master plan for the
City of Folsom’s historical downtown/redevelopment area that
encompassed 970 acres in two major watersheds. The master
planning effort included determining the capacity of existing
drainage facilities, identifying existing deficiencies,
evaluating impacts of future growth, determining required
facilities to meet future needs and improve existing
deficiencies, and determining maintenance needs.
West Yost prepared a drainage master plan for the Town of Loomis
with three main objectives: evaluating existing flooding
problems, identifying potential improvements, and preparing
drainage utility maps. The Town did not have storm drain utility
maps, therefore, significant effort was devoted to
developing these maps. This project also included incorporating
the 100-year floodplain into the utility mapping, developing
flood control facilities, preparing facility cost estimates, and
developing a storm drain maintenance program.
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 prepared the Downtown Drainage Master Plan for the City
of Rocklin. The Downtown Drainage Master Plan quantified the
present runoff from the study area to the creeks; identified
drainage problems; determined the capacity of existing drainage
facilities; and developed drainage policies and design criteria
for the master plan.
West Yost developed the first storm drain master plan for the
City of Napa. The master plan included: the development of
updated planning and design criteria for the development
standards, preparation of hydrologic and hydraulic evaluations of
existing drain facilities, evaluations of documented problem
areas, preparation of cost estimates, development of recommended
capital improvements, completion of a financial plan and
preparation of the initial environmental study on the master plan
recommendations.
West Yost updated the flood control master plan for the Ulatis
Creek Watershed. The objectives were to determine the City of
Vacaville’s existing level of flood protection along the major
creeks draining through the City, evaluate flood control
alternatives to increase the City’s level of flood protection,
and identify preferred projects for implementation within each
watershed.
West Yost performed a master drainage study for the City with
complete review and analysis of applicable hydrologic models and
development of a recommended Capital Improvement Program. West
Yost also provided planning and design services for storm
drainage infrastructure including detention ponds and pumping
stations.
West Yost prepared a Storm Drain Master Plan for the City of
Manteca and developed a $17.6 Million Capital Improvement
Program. West Yost also led a stormwater management utility fee
study to identify the financial needs and revenues to operate and
maintain the storm drain facilities, including the
newly-identified stormwater quality improvement program according
to the City’s NPDES Phase II permit.
The University of California, Davis campus is the largest campus
in the UC system, spanning over 5,500 acres across two counties
(Yolo and Solano). West Yost prepared a campus-wide storm
drainage master plan, that included a detailed capital
improvement program to meet existing and planned growth.
After preparing the VSFCD Flood Control Master Plan, West Yost
provided on-call modeling and design services on serveral
projects for the District. This included preparing the design of
a headwall, trash rack, and access road for an open channel
within Setterquist Park, reviewing a Caltrans plan to enlarge
three culverts under I-80, and developing a low-cost storm
drainage improvement plan to address increased flows through the
Caltrans culverts.
West Yost routinely provides support of EIR and General Plan
efforts for communities throughout California, specifically in
the area of flood control and storm drainage.
