Flood Plain Analysis

CLOMR study for 144th Avenue Bridge

City of Thornton
Thornton, Colorado
CLOMR study

JFSA was the prime consultant for the design of a new bridge over Big Dry Creek at 144th and about 5000 feet of roadway improvements. JFSA performed the hydraulic studies to determine the opening and height of the bridge and prepared a CLOMR.

Project Highlights:
Objective:
  • Roadway and drainage improvement project
Important Features:
  • Due to absence of FEMA model, developed a new effective model
  • Resolved hydrological difference between adjacent FEMA studies through discussion with UDFCD
  • Interacted with regulatory agencies, including UDFCD, FEMA, and Adam County
  • Used HECGEORAS to produce floodplain maps
Transmission Facility CLOMR study for 144th Avenue Bridge
Flood Insurance Study Flood Insurance Study
Flood Insurance Studies Flood Insurance Studies
LOMR Study for Sand Cree LOMR Study for Sand Creek, Powers Boulevard
Letter of Map Amendment Letter of Map Amendment, Pinecrest Trout Ranch

CLOMR study for 144th Avenue Bridge

City of Thornton
Thornton, Colorado
CLOMR study

JFSA was the prime consultant for the design of a new bridge over Big Dry Creek at 144th and about 5000 feet of roadway improvements. JFSA performed the hydraulic studies to determine the opening and height of the bridge and prepared a CLOMR.

Project Highlights:
Objective:
  • Roadway and drainage improvement project
Important Features:
  • Due to absence of FEMA model, developed a new effective model
  • Resolved hydrological difference between adjacent FEMA studies through discussion with UDFCD
  • Interacted with regulatory agencies, including UDFCD, FEMA, and Adam County
  • Used HECGEORAS to produce floodplain maps

Flood Insurance Study

FEMA
Winter Park, Colorado
Flood Insurance Study

JFSA performed flood studies for the community of Winter Park in Grand County, Colorado. Studies included hydrologic and hydraulic analyses, as well as extensive field surveys of 26 bridges and channel sections. The hydrology study addressed the derivation of flood peaks from snowmelt or thunderstorm and impacts of major stream diversions.

Project Highlights:
  • Hydrologic analysis using impacts of thunderstorm and snowmelt
  • Hydraulic Modeling of 26 proposed Bridges
  • Iterative bridge modeling for reduction of floodplain impacts on Right of Way

Flood Insurance Studies

FEMA
Arapahoe, Douglas, and Teller Counties
Flood Insurance Studies

JFSA's tasks included approximately 31 miles of detailed study reaches, 136 miles of approximate study reaches, approximately 15 major existing bridges, and a number of proposed new bridges. JFSA worked with developers in determining the optimum configuration of the bridge to minimize encroachment into the floodplain.

Project Highlights:
Objective:
  • Study completed as part of flood insurance studies
Important features:
  • Hydrologic and hydraulic studies for 31 miles of detailed study reaches
  • Hydrologic and hydraulic studies for 136 miles of approximate study reaches
  • Hydraulic studies for 15 major existing bridges

LOMR Study for Sand Creek, Powers Boulevard

Colorado Department of Transportation
El Paso County, Colorado
LOMR Study for Sand Cree

The reach at the project location had undergone many changes and improvements that were not reflected in the current FIS study. A LOMR by JFSA was prepared to incorporate these changes.

Project Highlights:
Objective:
  • Study was completed as part of an environmental assessment
Important Features:
  • Created duplicate effective model in HEC-2 and then converted to HECRAS
  • Included channel improvements such as drop structures, bank stabilization in the proposed HECRAS model
  • Used Pikes Peak Area Council Government data to supplement FEMA information
  • Completed individual notification to landowners as part of LOMR process

Letter of Map Amendment, Pinecrest Trout Ranch

Mount Evans Trout Fishing LLC
Mount Evans, Colorado
Letter of Map Amendmen

This is an example project where JFSA completed a flood study and had a LOMA approved so that the landowner may be exempted from buying flood insurance.

Project Highlights:
Objective:
  • Study was completed as part of a flood map amendment application
Important Features:
  • Survey and mapping to determine elevation information
  • Hydraulic calculations to determine 100-year depth and floodplain
  • Preparation of LOMA application
  • Property exempted from buying flood insurance