Watershed and Geologic Science


Hydrologic modeling using HEC-1, HEC-HMS, FLO-2D Two Dimensional Modeling and other state and local models for determination of flood peak flows and flood hydrographs for floodplain studies, flood insurance rate mapping, area drainage master plan and drainage design purposes.  Hydrologic modeling is performed using various methods including Green-Ampt, SCS methods and other state and local methods for rainfall runoff.

Hydraulic modeling including HEC-2, HEC-RAS, HEC-GeoRAS, FLO-2D and numerous other state and local applications for determination of floodprone areas and proposed flood control and drainage design projects.  Hydraulic modeling is prepared by JEF for many purposes including flood insurance mapping, floodplain mapping for hazard and damage assessment, impacts due to urbanization, fire and other man-made influences, floodplain hydraulics for effects on bridge, culvert, channel, levee and dam design.

Project Highlight: SR86 – Valacia to Kinney – FLO2D Hydrol






Watershed & Geologic Science – Applied Geomorphology

Geomorphology is the scientific study of the physical features of the earth’s surface. JEF is an industry leader in applying the science of geomorphology to solve real-world engineering problems and to manage natural hazards in the arid west.  Our expertise includes:
– Alluvial Fan Flood Hazard Assessment
– Riverine Erosion Hazard Delineation
– Scour & Sedimentation Analyses
– River Stability Studies & Master Plans
– Stream Restoration
– Fluvial Geomorphology
– Geomorphic & Surficial Geologic Mapping
– Paleoflood Studies
– Flood Frequency Analyses
– Natural Hazard Evaluation

JEF’s experience in applied geomorphology spans the entire western United States.  We have helped engineers, planners, and attorneys from private and public entities better understand how the built environment will be impacted by natural processes.

Project Highlight: YCFCD Historical Photography Collection