Integration with USGS MODFLOW
FLO-2D has a number of new features. The primary new component is the USGS groundwater model MODFLOW that has been linked with the FLO-2D model for surface-groundwater flow simulations. The two models can exchange surface flow to groundwater or vice versa. The model simulation is controlled by the FLO-2D model timesteps which are typically smaller than the MODFLOW model.
Run time optimization
The FLO-2D model is being optimized to take advantage of parallel computation in multiple processor computers. This is an on-going task. Runtime speeds have increased from 1.5 to 2.5 times. We anticipate significant reductions in simulation times over the next year as more OpenMP code is embedded in the model.
Levee breach simulations
The Corps of Engineers fragility curves for levee and dam breach methodology was added to the FLO-2D beach component in Version 2009. This will enable the prediction of levee failure locations. The application of fragility curves integrates geotechnical risk with the computation of flood hydraulics. This tool will enhance the prediction of levee breach floodplain storage with downstream flood attenuation.
Importing HEC-RAS projects
Existing HEC-RAS data files can now be imported to the GDS and used to locate channels and create the FLO-2D cross section and channel data files. HEC-RAS cross sections can be interactively assigned to channel elements, allowing its integration with the 2-D floodplain 2-D grid.
Other new tools
The GDS and Mapper have a number of new tools, features and displays including watershed delineation, 3-D ground surface plots, and new channel cross section analysis.
New frequency analysis software
FreqPlot is our new rainfall and flood peak discharge frequency analysis program that significantly improves evaluations in a quick and convenient manner. Four frequency plotting distributions including extreme value, log extreme value, normal, and log normal (Log Pearson III) can be reviewed simultaneously to determine which frequency distribution provides the best fit to the data.
New RiverFLO-2D Model
RiverFLO-2D is a two-dimensional hydrodynamics model for river and floodplain routing. This software was released in January 2009. It is a finite element model that complements the FLO-2D model by computing flow hydraulics and sediment transport with rigid or mobile bed. Flexible triangular meshes can be generated and refined around key river features, generating detailed velocity fields for rivers, overbank flooding, and dam break simulations. The model can simulate both steady and unsteady flows with wetting and drying allowing initial dry river bed without spin-down or other cumbersome procedures.
Big Hole River Diversion Dam Overhaul
The Big Hole River Diversion Dam, located near Divide, Montana is a municipal water intake structure, owned and managed by the City and County of Butte-Silver Bow (BSB), Montana, and serves as Butte’s main source of potable water. The existing concrete diversion dam and associated intake structure is approximately 80 years old and is in poor condition. The structure is a also barrier to fish passage and a safety hazard for public recreation.
BSB tasked DOWL KHM of Butte, MT with the design of a replacement structure. The purpose of the project is to provide reliable water, accommodate fish passage, and improve structure safety. Due to the design complexities, conventional one-dimensional models were considered inappropriate for evaluating the hydraulic performance.
RiverFLO-2D was selected to simulate highly detailed 2-D hydrodynamics around the complex structure. The model was successfully calibrated to flow conditions at the existing dam and was then used to complete the design consisting of a trapezoidal rock weir spillway and a series of plunge pools. Modeling results are being reviewed by state and federal permitting agencies.

1. Finite Element Mesh on the Intake

2. Velocity Field on the Intake
For additional information regarding this project contact:
Dick Talley, PE at DOWL HKM, Butte, MT (406) 723-8213.
For more information about RiverFLO-2D please go to:
http://www.flo-2d.com/products/riverflo-2d/
Swimming Downstream (and looking ahead)

We anticipate significant changes to the FLO-2D model landscape for the next version in 2011 including a storm drain model, geo-referencing components and variable size grid system. We are currently working on runtime linkage to XP Software’s storm drain model. This new component will enable FLO-2D urban surface flooding simulations to interact with pressure storm drain flows on a computational timestep basis. Flow will be exchanged between the two models with floodwaters entering the storm drains and storm drain flow returning to the surface model. With the existing street flow component and the component for the loss of storage and flow obstruction due to buildings, the storm drain component will complete the FLO-2D urban model.
In the next release, the FLO-2D GDS processor program will have geo-referenced components (such as channels, streets, levees, infiltration, etc.) that will be independent of the grid system. This will enable the grid systems to be revised or completely recreated without re-assigning the components to a new grid system. The user will be able to convert a FLO-2D model with a 300 ft grid system to a 100 ft grid system seamlessly.
In conjunction with the geo-referenced components, we will introduce variable size grid systems which will permit smaller grid elements within a large grid system. Where higher resolution near the project site is required, the user will be able to reduce the grid system as a multiple of 2, 4 or 16 in order to refine the flow dynamics without significantly impacting the entire simulation.
Outreach
California: In 2007 FLO-2D was selected by the California Department of Water Resources to simulate the floodplain hazard for the Central Valley Floodplain Evaluation and Delineation Program. When completed, this program will result in the largest ever state-funded levee evaluation and floodplain delineation program in the Nation. The program will enter the flood simulation phase in the coming months.
Arizona: FLO-2D Software, Inc. recently signed a contract with the Flood Control District of Maricopa County encompassing the City of Phoenix, Arizona to provide engineering services and training related to hydraulics, sediment transport, and other advanced river issues based on the FLO-2D model over a 2-year period. This represents an opportunity to develop new FLO-2D tools for flood routing with the District.
Hungary: The Water and Environmental Damage Control Department of the Ministry of Environment and Water is evaluating the FLO-2D model for application on the Tisza and Danube Rivers for the design of flood mitigation detention basins. If successful, the Department may initiate training and application of the model to other water districts in the country.
|