Representative projects include:

Task orders under this contract included:

• Providing training in HEC-HMS, HEC-RAS, and reservoir system analysis.
• Sediment and nutrient investigations for HEC-HMS.
• Support for HEC-EFM.
• Development of an outline for the Iraq water resources master plan.
• Evaluation of hydrologic and hydraulic models for the Namakan and Rainy basin.
• Independent technical review of the Folsom Reservoir operations model.
• Enhancement of HEC-HMS and HEC-PRM.
• Replicating in HEC-ResSim the HEC-5 applications for the Alabama-Coosa-Tallapoosa and Apalachicola-Chattahoochee-Flint watershed.
• Review of using the soil moisture accounting algorithm for CWMS.
• Revision of several Corps guidance documents.
• Investigation into the integration of HEC-EFM into the HEC-WAT suite of software tools.
• Regional skew analysis of the Delaware River basin.

Task orders under this contract included:

• Technical assistance and independent technical review (ITR) for the Corps’ Folsom operations.
• Concept design for the Sacramento District’s water control decision support system.
• ITR of the hydraulics and hydrology related to the Upper Feather River Floodplain Mapping Study.
• Hydrologic and hydraulic analyses for DWR’s Floodplain Mapping of the Central Valley.
• Review of the Delta Risk Management Study products.
• Interior analysis near Hamilton City, CA.
• Development of a coincident frequency analysis framework for tributary streams.

Work on this project includes tasks to:

• Simplify, accelerate, and automate the release data from New Bullards Bar Reservoir by developing a tool called FlowCat—flow calculator and transmitter system. FlowCat consists of 2 programs: a graphical user interface that allows powerhouse operators to enter and view data, and FlowCat Service, a Windows service that reads data from the powerhouse computer and sends data to the California Data Exchange Center (CDEC).
• Identify, specify, acquire, and deploy hardware and software for the F-CO decision support system. Our work included development of necessary scripts and software applications to implement and deploy the automated reservoir simulation system on a Linux server.

As part of the larger Sacramento and San Joaquin River Basins Comprehensive Study, we were asked to identify problems, opportunities, and objectives; inventory and forecast conditions; formulate alternative plans; evaluate effects of alternative plans; compare alternative plans; and select a recommended plan. The project occurred in 4 phases: (1) engage stakeholders in consensus building, investigate baseline conditions, and identify opportunities for enhancement; (2) formulate and screen measures; (3) evaluate proposed plans; and (4) prepare draft feasibility report.

The Three Rivers Levee Improvement Authority (TRLIA) asked us to evaluate the risk and economic consequences of flooding under the proposed Feather River levee improvement alternatives, using procedures that would be acceptable to the Corps of Engineers and to the California Department of Water Resources. We computed economic benefits for 4 proposed inundation-reduction alternatives. To develop information on flood risk and flood damage as it relates to the sequence of construction and development, we computed a numerical index of flooding—the annual exceedence probability, and a numerical index of risk of flooding—the expected annual damage. For the statistical analysis, we used the Corps’ HEC-FDA program, and applied Corps uncertainty analysis methods to compute EAD for the without-project condition and each alternative.

In this water control data system development and deployment project, LCRA selected us to design, configure, and implement a stand-alone decision support system for the lower Colorado River basin using the Corps Water Management System (CWMS). To do this, we did the following:

• Formulated a design, identifying actions and tools necessary to implement CWMS.
• Assisted with the design of the data acquisition plan.
• Acquired, ported, and integrated watershed models and databases with CWMS components and configured CWMS to recognize and use those models and databases.
• Developed and carried out a testing plan.
• Provided training and support for CWMS implementation.

To prepare for briefings before the California legislature, the California Department of Water Resources asked us to hypothesize, simulate, and analyze a plausible levee failure scenario for the city of Sacramento. Our tasks included:

• Using hydraulic models to simulate a high flow event that results in Sacramento area levee failures.
• Using the hydraulic model results and GIS tools to map the resulting floodplains.
• Using GIS tools to calculate and prepare maps showing the depth of flooding resulting from the breaches.
• Using the developed floodplain to estimate the direct tangible property damage, potential loss of life, effect on critical facilities, utilities, and transportation systems, displacement and temporary housing costs, and impact to the regional economy.

In this regional analysis, we were asked to develop the hydrology to “feed” the North Delta HEC-RAS model. This hydrology includes runoff hydrographs from the Cosumnes River, Dry Creek, Mokelumne River, and Morrison Creek watersheds. We:

• Identified locations at which flows are specified as boundary conditions.
• Reviewed existing watershed models for the subject watershed, accepted a model for each watershed to use in this analysis, and modified the accepted watershed models as necessary to account for new information, modified conditions, and additional computation points required.
• Analyzed the statistical correlation of flows from the contributing watersheds to the North Delta to determine the spatial distribution and coincident frequency of design storm rainfall (concurrent precipitation and flow) for our rainfall-runoff modeling.
• Completed a precipitation frequency study to develop the appropriate rainfall depths for various durations and frequencies for the watersheds so that design storms could be defined.
• Evaluated the effect of snowmelt on runoff computations.
• Determined the precipitation for the selected design events, loss rates, and baseflow, reviewed reservoir operation criteria, and used that information to modify boundary conditions and parameters of the accepted watershed models.
• Computed hydrographs of known frequency for the events required.
• Identified peaks and assigned probability to the peak equal to the probability of the rainfall.
• Evaluated the ability of the models to convert accurately precipitation to runoff by comparing our computed runoff coefficients with coefficients previously developed for this watershed and by comparing the results to other data sources, such as developed and established flow-frequency functions.