E&H works on problems in engineering hydrology in
diverse settings throughout the world.
See a world map showing locations of
our projects.
Or review a list of our clients.
Here's a snapshot of selected projects in each of our focus
areas:
The Blue River discharges from Dillon Reservoir near the town of Silverthorne, Colorado. The hydrology and sediment loads of the river were completely altered with the construction of Dillon Dam. In response, the morphology of the system has changed through time. Engineering & Hydrosystems Inc. worked with Ecological Resource Consultants Inc. to analyze the river and prepare restoration designs. The objectives of the project included restoration of aquatic habitat and establishment of the appropriate channel morphology. The proper geomorphology is based on the altered stream hydrographs limited inflowing sediment. Project work included fluvial geomorphologic analysis and design, detailed analysis of the fluvial hydraulics of the river, engineering design of vegetation requirements and root architecture, selection and establishment of new vegetation on point bars, floodplains and benches, and design of pools and riffles.
This project won the “Project of the Year Award in the Utility Drainage and Environmental –
Small Communities Category by the Colorado Chapter of the American Public Works Association”
and “Colorado Trout Unlimited Exemplary Project Award.”
The Eagle River that flows past the town of Minturn has been significantly impacted by human activity, including mining and urban development. Engineering & Hydrosystems Inc. worked with Ecological Resource Consultants Inc. to analyze the river and prepare restoration designs.
The objectives of the project included restoration of fish and other aquatic habitat and re-establishment of the channel cross section, meander pattern, profile, and benches and floodplain of the river.
Project work included fluvial geomorphologic analysis and design,
detailed analysis of the fluvial hydraulics of the river, engineering
design of vegetation requirements and root architecture, selection
and establishment of new vegetation on point bars, floodplains and
benches, and design of pools and rifles.
Engineering & Hydrosystems Inc. was responsible for determining the impact of one of the largest housing developments in the San Francisco Bay Area on the West and Main Branches of Alamo Creek, California. The project entailed a fluvial geomorphologic assessment of the creeks, assessment of sediment yield impacts, hydraulic modeling using HEC-RAS and sediment transport modeling using MIKE11.
Designs to stabilize and restore
the river were prepared to conform to natural processes as closely
as possible. A unique feature of the project was the
synthesis of engineering and ecological restoration
techniques. The Erodibility Index Method developed
by Dr. Annandale, E&H Principal, was used to quantitatively
determine the root architecture requirements of plants to
withstand the anticipated erosive forces of water flowing
in the creeks, adjacent to creek banks and on the floodplains.
This information was used by the project restoration ecologist
from LSA Associates and landscape architects Nicol and Associates
to select plant material for creek stabilization.
Engineering and Hydrosystems Inc. simulates sediment transport in Irian Jaya, Indonesia using HEC-6T and MIKE-11 software. The modeling results are used for the development of environmental protection programs. An extensive levee system was constructed to protect the surrounding areas against environmental degradation and flooding. The sediment transport modeling executed by Engineering and Hydrosystems Inc. predicts sediment level changes over a 38 year period and the volume of sediment that will flow into the Arafura Sea. This information is used for Environmental Risk Assessment.
Engineering and Hydrosystems Inc. (E&H)) was commissioned by Landsvirkjun, Iceland to investigate scour potential in the canyon downstream of the Kárahnjúkar Dam where the spillway will discharge water into the Jökulsá á Dal. The Kárahnjúkar Dam will store water from the Vatnajökull glacier to generate hydroelectric power for use by the Alcoa Smelter that will be built in the east of Iceland.
The overall objective of the study was to investigate the scour potential of the canyon bed and walls that will be subjected to discharges from the spillway on a regular basis. The scour analysis itself was conducted by making use of two approaches: the Erodibility Index Method ( Annandale 1995) and the Comprehensive Scour Model.
The preliminary investigation indicates anticipated scour of tens of meters that will not only
impact the canyon bed but is also expected to lead to instability of the canyon walls. E&H will be
providing the additional evaluation of the scour potential and recommending design alternatives
for protection of the canyon walls.
Engineering & Hydrosystems Inc. (E&H) analyzed foundation scour potential for Smith Mountain
Dam, Virginia as part of a FERC re-licensing process. The dam is expected to overtop under
Probable Maximum Flood (PMF) conditions and, in accordance with FERC regulations, required
assessment of dam foundation scour. The 235 ft high double-curvature arch dam is founded on
rock. The analysis required implementation of the Erodibility Index Method (Annandale 1995)
that was developed by one of E&H’s principals to determine scour potential of the rock
foundations. E&H also made use of recent research in Switzerland to conduct a fatigue analysis
for determining the rate of scour.
Engineering & Hydrosystems, Inc. was commissioned to evaluate the scour potential of the rock foundation on the downstream side of the Eagle Nest Dam when subject to overtopping. The methods used to evaluate site conditions were the Erodibility Index Method (Annandale 1995) (EIM), the Comprehensive Fracture Mechanics approach (CFM) and the Dynamic Impulsion Method (DIM).
By applying all three methods to analyze rock scour it was possible to draw conclusions pertaining to the scour potential under Probable Maximum Flood (PMF) conditions. The scour analysis was conducted for the area immediately downstream of the dam that will be impacted by the overtopping jet which was modeled during PMF conditions. Scour potential of the existing spillway on the left bank was assessed by inspecting the rock and making a judgment call as to its potential vulnerability. Based on the information that was generated during the jet scour analysis it was possible to assess the spillway performance and that of its discharge area without detailed calculation.
It was determined that scour potential at the base of the dam during an overtopping event
could occur in two possible modes; instability of the rock on the left abutment, and scour
potential by fatigue of the rock foundation in the downstream impingement zone.
Engineering & Hydrosystems Inc. was commissioned by Metropolitan Water District to determine
the potential scour depth of Santa Gertrudis Creek in southern California. The project was unique
because of the high erodibility of the bedrock (soft, poorly-cemented sandstone). It was
determined that the creek was in a state of dynamic equilibrium with current hydrologic and
sediment conditions and minimal. It is not expected that large-scale degradation or lateral
migration would occur given the existing conditions. However, the watershed has been zoned for
commercial and residential development. Predictive hydrologic modeling indicated that the runoff
from the watershed could increase by a factor of 10. If these conditions exist, it is likely
erosion in the area of interest could be significant. It was proposed that if any land is
developed, grade control structures must be constructed.
Engineering & Hydrosystems Inc. was commissioned by Metropolitan Water District to determine the cause of degradation of the Whitewater River, California and to design erosion protection for the Colorado River Aqueduct pipeline crossing.
Investigation of the degradation and preparation of sustainable fluvial designs to protect the pipeline against exposure were approached from a geomorphic analysis point of view. Geomorphic analysis of rivers or streams requires a systematic and organized approach because of the spatial scale and system complexity involved. The approach used is a tried and tested method for stream reconnaissance together with a blueprint for fluvial hydraulic studies and geomorphic studies.
The catchment baseline and geomorphic investigation revealed that degradation was present
throughout the watershed. It was determined the main cause of degradation was channel straightening
and confinement, particularly on the historical alluvial fan. The sediment transport model allowed
for an understanding of a sediment balance and a degradation rate was calculated. Additionally E&H
calculated single-storm scour depths at the crossing. These specific steps allowed E&H to define
the problem before designing the appropriate erosion protection at the site.
Engineering and Hydrosystems Inc. executed a project for the World Bank in
Sri Lanka to develop strategies for sustainable management of water resources
and water resource infrastructure. The project entailed analyzing the reservoirs
in the Mahaweli River system to determine the technical feasibility to remove
sediment from reservoirs using six optional reservoir sedimentation management
techniques. An economic optimization was conducted on the feasible sustainable
and non-sustainable options including a ‘do-nothing’ alternative to identify
the most economical technique for management of the system of reservoirs. The
technology that was used to execute the project is based on a method that was
developed for the World Bank by Engineering and Hydrosystems Inc. in cooperation
with resource economists from the University of Connecticut.
Click here to learn more about this project and the RESCON work sponsored by the World Bank.
Engineering and Hydrosystems Inc. executed a project for the World Bank in Morocco to develop strategies for sustainable management of water resources and water resource infrastructure. The project entailed analyzing ten reservoirs to determine the technical feasibility to remove sediment from reservoirs using six optional reservoir sedimentation management techniques. An economic optimization was conducted on the feasible options to identify the most economical management technique for sustainable management of the reservoirs. The technology that was used to execute the project is based on a method that was developed for the World Bank by Engineering and Hydrosystems Inc. in cooperation with resource economists from the University of Connecticut. Click here to learn more about this project and the RESCON work sponsored by the World Bank.
Engineering & Hydrosystems Inc. is developing dam breach models
for the Maricopa County Flood Control District as part of their
dam safety assessment program. The models that are developed are
unique because they are physically based and take account of both
the erosive power of water and the relative ability of earth material
to resist erosion. Models have been developed to simulate the rate
and overall dimensions of dam breaching that can result from transverse
cracks in earth embankments, from piping failure due to round or
rectangular imperfections in embankments and due to ground fissures
that can develop in the dam foundation. The model has the ability
to simulate spatial variation of the erosive power of water due to
changes in the breach geometry, taking account of laminar, transition
and fully turbulent flows through the breach. Sensibility testing is
done by comparing predictions made by the model to the size of
breaches and development time of actual failures of earth embankments.
Breach size and time of development are critical factors determining
economic impact of dam failure.