Flood Mapping, River Restoration, and Dam Failure Investigation

EA provides inundation mapping services to our clients that inform the public of flooding risk. Using a combination of hydrologic, hydraulic, and mapping expertise, EA produces inundation maps that are accurate and easy to comprehend. These maps are essential for emergency responders to rapidly evacuate residents downstream of a dam if an issue were to arise. EA also provides FEMA permitting and river restoration mapping services using similar tools.

Flood Mapping

EA provides flood determination services through inundation mapping for a variety of applications. Inundation maps illustrate the spatial extent and depth of flooding at specific water-level intervals. Accurate location of floodplain boundaries is an essential part of public safety. EA creates detailed floodplain models through hydraulic modeling software, such as HEC-RAS and FLO-2D. The hydraulic modeling results are mapped using ArcGIS and are catered toward the needs of the specific project requirements. The result of our hydraulic modeling and GIS mapping is accurate and informative inundation maps. A few of our inundation mapping services include FEMA permitting, hazard classification of dams, instream hydraulic structure design, spillway and drop structure design, and Emergency Action Plan (EAP) development.

Extreme Precipitation Event Studies

Hydrologic probable maximum precipitation (PMP) and frequency storm routing is required for most river and dam projects. EA works closely with the State Engineer’s Office to keep our methodology current and relevant to the area of work. Most projects have an upstream catchment and a design storm associated with the project. As this design storm can have significant effects on the project, EA takes into consideration all hydrologic assumptions so that the final product is safe and cost effective. Highlighted areas our staff specialize in are extreme precipitation routing, watershed studies, and spillway and culvert design.

Breach Analysis

EA’s staff has provided dam breach analysis and potential hazard analysis for nearly every dam we work on. Dam breach analyses are used to estimate the potential hazards associated with the failure of an embankment/dam structure. Accurate modeling and sound engineering judgment are necessary in selecting the appropriate breach analysis type for each project. EA’s engineers have used one-dimensional (HEC-HMS) and two-dimensional (HEC-RAS) prediction models in developing the outflow hydrograph routing.

Emergency Action Plan Preparation

EA’s water resource engineers have developed Emergency Action Plans (EAP) for our dam owners throughout our tenure. EAPs identify potential emergency conditions and specify preplanned actions to help minimize property damage and loss of life should those conditions occur. Our mapping services are personalized toward the emergency response personnel who will be using the EAP maps. Each map contains important features, such as house locations, depths of flow on access roads, and time of arrival of the flood wave.

Dam Failure Investigation

EA has provided forensic investigations for cases involving water storage dam and tailings dam failures. Our dam failure evaluation experience includes seepage analysis, identifying contaminant source, slope stability analysis, evaluating tailings dam stability, cover cracking evaluation, liner design, water balance calculations, and remediation cost allocation.

Flood Mapping, River Restoration, and Dam Failure Services

Engineering & Design
  • Site civil design
  • Dam design, storage and delivery
  • Hydraulics and hydrology
  • Geotechnical design
  • Geologic analyses, geologic hazards
  • Forensic studies, litigation support
  • Construction management
Environmental Monitoring & Compliance
  • Permitting, compliance
  • Stormwater management
  • Health & safety

Hydrologic and Hydraulic Engineering

Construction Materials Testing
  • Field engineering
  • Soil, concrete, asphalt testing
  • Quality assurance/quality control
  • Geotechnical laboratory testing

Our clients rely on us for conceptualization, planning, engineering design, cost estimation, funding procurement, permitting, and construction management.