Angel Park Detention Basin Expansion

Project Type: Flood Control Facility
Construction Budget: $8,300,000
Client: City of Las Vegas
Service Performed:
  • Detention Basin Design
  • Hydrology
  • Hydraulics
  • Right-of-Way
  • Grading
  • PMF Spillway Design
  • Structural Engineering
  • Utility Coordination
  • Mapping
  • Water Quality Feature Design
  • Access Roads and Ramps

GCW prepared detailed hydrologic and hydraulic analyses and designs for the
Angel Park Detention Basin Expansion. Facilities include additional excavation of
approximately 200,000 cubic yards and grading of the existing detention basin to
increase storage capacity from the designed 1,400 acre-feet to 1,629 acre-feet,
approximately 5,000 linear feet of 18 inch storm drain, perimeter access roads,
a gabion drop structure, water quality features, and a PMF spillway. Design
100-year inflow into the detention basin is 9,200 cfs. Work inc ludes hydrology,
PMF hydrology, detention basin hydraulics, gabion drop structure design, PMF
spillway design, utility coordination, storage volume calculations, earthworks
volume calculations, contour grading of the basin, plan and profile of storm drain,
design of perimeter access road and access ramps. The PMF spillway will convey
approximately 7,000 cfs. This project will be the first project in the Las Vegas Valley
to design and construct water quality features into a detention basin as required
by the Storm Water Management Plan. The water quality features consists of
a storage volume of 85-acre-feet, intended to drop sediment out during more
frequent storms like the 2- to 5 year event, while not impacting the 100-year
storage volume. Services include right-of-way engineering, coordination of
environmental assessments and of submittals for approval with local, regional and
state entities. Right-of Way services include right-of-way mapping, identification
of property ownership and constraints, and preparation of legal descriptions for
easements.