Water Resources Archives

Simulating Compound Flooding During Hurricane Harvey with AdH

Simulating Compound Flooding During Hurricane Harvey with AdH Harris County, Texas DCCM was tasked by the USACE ERDC Coastal Hydraulics Laboratory to utilize and test an in-development version of the Adaptive Hydraulics Model (AdH) software to complete a monolithic simulation of Hurricane Harvey compound flooding that occurred in August 2017. Many efforts investigating the effects of compound flooding have relied on discrete models that simulate each flooding process separately. Consequently, they fail to mechanistically account for the complex interaction of multiple flood processes and the resulting impact on hazard estimates. Novel capabilities of AdH enable economical simulations of very large model domains while providing a high-resolution description of flood hazards in two dimensions. AdH provides the capability to simultaneously implement spherical coordinates and solve the shallow water equations and diffusive wave equations within a simulation. The combination of these capabilities makes AdH an effective model to simulate rainfall, overland flow, and storm surge to produce estimates that account for the interacting effects of pluvial, fluvial, and coastal flooding. Model terrain derived from LiDAR provided a high-resolution description of topography and large river channel bathymetry was resolved. Spatially and temporally variable rain rates and wind fields within the model resolved heterogenic storm characteristics. Model results were compared to stage and discharge time series observations at over 30 locations throughout Harris County and Galveston Bay. Modeled peak stages are within 1 m of observed peaks at more than 80% percent of the stations. The methods presented here can serve as a template for estimating flood hazards that result from compound flood events, and the results have documented the ability to mechanistically account for the interacting effects of multiple flood processes with a 2-D hydrodynamic model. At a Glance $168,500 Project Cost Markets Water Government Services Water & Wastewater

Artesian Slough Hydraulic Model and Closure Structure Conceptual Design

Artesian Slough Hydraulic Model and Closure Structure Conceptual Design Santa Clara County, California DCCM was contracted by the USACE San Francisco District to complete a hydraulic analysis and conceptual design for a water control structure on Artesian Slough. The San Jose – Santa Clara Regional Wastewater Facility (SJRWF) discharges effluent to the upper end of Artesian Slough, which terminates in South San Francisco Bay. An engineered levee is proposed to cross Artesian Slough and a gated outfall structure is required at the levee crossing to allow SJRWF effluent discharges to pass while protecting areas behind (south) the levee during extreme high tide events. A 2D HEC-RAS model was constructed representing the existing site conditions and calibrated to observed water level data above and below the SJRWF weir. A 1D model was also developed and calibrated for rapid simulations of various closure culvert designs. With-project conditions (WPC) 2D and 1D models were developed. The 1D WPC model was utilized to perform the closure design analysis. Sea-level rise (SLR) estimates were computed for the area based on the Coyote Creek tide gage and the USACE high SLR curve. The models were run for current and year-50 tidal signals, adjusted by the SLR curve. A total opening area of 210 square feet was selected to minimize the increase in water surface elevations upstream of the structure while considering cost-efficiency. The conceptual design was informed by the hydraulic analysis and looking ahead to maximize cost efficiency, be readily constructable, and minimize maintenance procedures and costs. It consists of six 72-inch by 70-inch culverts for a total opening of 210 square feet. The conceptual design has two sets of 3 culverts spaced closely together near each wing of the closure, with staggered outlets turned 90-degrees inward, which improves construction and maintenance efficiency. The conceptual design was translated to the 2D HEC-RAS model and run for six cases of varied tidal conditions, SJRWF outflow, and sea level. The water level results from the 2D HEC-RAS model were modified for areas above closure structure to account for the 90-degree bends recommended in the conceptual design. The water level, velocity, and shear stress results from the cases tested in the 2D model of the conceptual design were used to make conclusions regarding closure operations and erosion potential. At a Glance $170,000 Project Cost Markets Water Government Services Water & Wastewater

Upper Mississippi River Dogtooth Island Peninsula Sediment Transport Study

Upper Mississippi River Dogtooth Island Peninsula Sediment Transport Study Thebes, Illinois, to Birds Point, Missouri DCCM completed a hydrodynamic and sediment-transport study to assess the risk of the Mississippi River forming a cutoff across the Dogtooth Island Peninsula following the Len Small Levee breach. The team developed a high-resolution, two-dimensional Adaptive Hydraulics model covering the Upper Mississippi River from Thebes, Illinois, to Birds Point, Missouri. The model evaluated three terrain conditions representing the levee before the 2016 breach, immediately following the breach, and after the 2017 flood. It was calibrated using data from the 2011, 2015–2016, and 2017 floods, with a focus on flows exceeding 400,000 cubic feet per second. Nine conditions were analyzed to evaluate floodplain shear stress, flow patterns, and sediment movement. The model also assessed structural and nonstructural alternatives, including an overflow weir, revetment closure, kicker dike, and grade-control improvements, to help USACE manage flow and sediment across the peninsula. At a Glance 400,000+ CFS High-Flow Model Calibration Markets Water Government Environmental Services Water & Wastewater

EFDC+ Salinity Modeling for Jacksonville Harbor

EFDC+ Salinity Modeling for Jacksonville Harbor Jacksonville, Florida With the expansion of the Panama Canal, ocean-going cargo vessels have increased in size to improve efficiency and carrying capacity. In order to accommodate the increasing drafts of these ships. Channel deepening projects can cause salinity intrusion into freshwater portions of the river system resulting in significant water quality impacts to the ecosystem. A coarse-grid model of a portion of the St. Johns River was originally developed for the Jacksonville Harbor Deepening Project Feasibility Study. DCCM was contracted by the Jacksonville District USACE to develop, calibrate and validate a more comprehensive and representative hydrodynamic and salinity water quality model of the Jacksonville Harbor. The model incudes 121 miles of the St. Johns River, adjacent wetlands and freshwater tributaries. The newly calibrated and expanded 3-D hydrodynamic model was developed using a newly developed version of the Environmental Fluid Dynamics Code (EFDC) and was used to evaluate the impacts of the channel deepening on salinity intrusion and stratification in the St. Johns River. The new multiprocessor version of EFDC was used to improve runtimes and the SIGMA-ZED vertical layering option within the gridding package was used to improve computational efficiency and the simulation of vertical stratification. In order to assess navigation channel modification impacts to circulation processes and salinity in the St Johns River, DCCM performed two simulations covering a 5 year-long period (2017-2022). The first simulation represented the existing channel bathymetry without deepening and the second simulation included the with-project (channel deepened) condition. Simulated water levels, flows, velocity, water age as a measure of residence time, and salinity were compared for each simulation. Numerous diagnostic simulations were conducted to evaluate contributions to increased salinity, difference between project induced salinity increases and salinity increases related to other processes such as freshwater flow variations, subtidal variations, offshore salinity variations, sea level rise, variations of wind velocities and directions. To improve the simulation of freshwater contributions from the adjacent watershed, DCCM evaluated and recalibrated existing HSPF watershed model. DSLLC processed USGS flow and groundwater data for the HSPF model, recalibrated the HSPF model and extended the simulation period. DSLLC then linked the recalibrated hydrologic model results as input to the Jacksonville Harbor 3D EFDC hydrodynamic model to simulate a more natural stormwater response from freshwater tributaries. The model results with the new EFDC Pre-Project model showed improved calibration and much shorter runtimes. At a Glance 121 miles 3D Hydrodynamic Model Domain 165 tributaries HSPF Hydrologic Model Area Markets Water Government Environmental Services Water & Wastewater

Bridgewater Villages 12, 13, and 14

Bridgewater Villages 12, 13, and 14 Lakeland, Florida DCCM provided boundary and topographic surveys, civil site design, permitting and construction services for the Villages at BridgeWater; a 620-acre residential development in Lakeland, FL. Civil site design included existing conditions/demolition plan, site grading & drainage, stormwater management, water service connections, sanitary sewer connections, erosion control plan and a Stormwater Pollution Prevention Plan. Survey tasks included retracement of Interstate Right-of-Way, platting phase services, research of survey, and Public Land System records as well as deeds and easements of record. Additional tasks included establishing horizontal and vertical control untilizing both GPS and leveling from established NGS control and researching and depicting the FEMA flood zone. DCCM also performed topographic and boundary survey of the golf course property. DCCM also provided zoning support as well as permitting coordination with the City of Lakeland, the Florida Department of Environmental Protection (FDEP), and Southwest Florida Water Management District (SWFWMD), and the Federal Emergency Management Agency (FEMA) for a Letter of Map Revision based on Fill (LOMR-F). At a Glance 620 Acres $153,910 Project Cost Markets Land Development Surveying Services Land & Site Development Surveying

Inwood Forest Stormwater Detention Basin

Inwood Forest Stormwater Detention Basin Houston, Texas The project included the conversion of 226-acres of golf course fairways into regional detention basins through an interlocal agreement between Harris County Flood Control District and the City of Houston. This project represents the largest single-phase dirt moving effort in the Flood Control District’s 88-year history. It is transforming the site into 12 interconnected compartments, designed to mitigate impacts of future City of Houston local drainage improvements and help reduce flooding risks in a historically vulnerable part of the city. The project encompasses property located both east of Antoine and west of Antoine, with a total of 12 interconnected compartments. The project is currently in construction and will provide approximately 1200 acre-feet of storage to the White Oak Bayou Watershed. At a Glance 226 Acres $71 million Project Cost “This project represents a historic milestone for Harris County Flood Control District, both in scale and impact. Converting more than 226 acres into interconnected regional detention basins required close coordination between agencies, thoughtful phasing, and precise execution. Once completed, the system will significantly enhance flood resilience for the White Oak Bayou watershed and surrounding communities.” Mark Rotz, PE Project Manager Markets Land Development Services Land & Site Development

Butler Beach Drainage & Stormwater Master Plan

Butler Beach Drainage and Stormwater Master Plan St. Augustine, Florida DCCM was tasked by St. Johns County to analyze the Butler Beach region’s drainage characteristics and study of how the region’s various sub-regions interact with each other. Our staff reviewed the existing drainage basin and identified areas of concern, which included the watersheds and stormwater infrastructure within the Butler Beach drainage area. Data was collected and analyzed from FEMA historic claims, Florida Department of Transportation infrastructure, field observations, Natural Resources Conservation Service (NRCS) soils information, current St. Johns River Water Management District permits, National Oceanic and Atmospheric Administration (NOAA) storm data, multiple field surveys and observations along with other data sources. In addition, a community forum/public meeting was held to identify other potential deficient areas. Each sub-region was evaluated, and recommendations were made for improvements. Maintenance considerations, capital costs and overall construction feasibility were considered. The proposed solutions were ranked based on the overall benefit cost analysis to assist the County in determining timing and funding of capital improvements to the drainage systems, overall effectiveness, ease of maintenance, feasibility of construction, and overall benefit to the sub-region. Finally, a detailed with report with full details for each potential solution was created and presented to St. Johns County. At a Glance 2.7 Square Miles Project Size $118,000 Project Cost Markets Land & site development Services Land & Site Development Water & Wastewater

Burkart Boulevard Bypass

Burkart Boulevard Bypass Seymour, Indiana This project involved constructing a 4.7-mile-long bypass around Seymour. The bypass extends from the US 50/Burkart Boulevard Intersection southwest and connects to the O’Brien Street intersection. The first phase of the project features a 99-ft. long bridge over the Conrail railroad, an MSE wall design that minimized the right-of-way footprint, a single-lane roundabout that can accommodate semi-truck and farm equipment traffic, and a new multi-use pathway along the project limits. The bypass also resulted in entirely new alignment and permanent traffic pattern changes. DCCM participated in extensive public involvement, continually coordinated with INDOT, the City of Seymour, and Conrail Railroad, and provided on-site and off-site mitigation efforts to accommodate all project features. At a Glance 4.7 Miles Project Size $17.2 million Project Cost ACEC State Finalist Project Award Markets Transportation Environmental Services Transportation Environmental Roadway Design Roundabout Structural Engineering Water Resources

Piper Road Drainage Improvements

Piper Road Drainage Improvements Brazoria County and Pearland, Texas DCCM provided design plans and specifications for a bid-ready submittal package that included comprehensive drainage and minor roadway improvements for Piper Road. The 2,900-foot project extended from FM 518 (Broadway Street) on the north to Fite Road on the south. The project included an asphalt overlay, along with subgrade repairs where necessary, based on visual cracking and pavement failure. The design reduced the watershed area for the portion of Piper Road draining to the north, which diminished a recurring ponding problem at FM 518. The majority of the roadway now drains to Fite Road on the south using storm sewers underneath the former ditches. Driveway culverts were eliminated for the storm sewers draining to the south and were replaced with area drains between the driveways for direct drainage into the new storm sewer system. Using storm sewers in this manner eliminated the need to do costly utility relocations or ROW acquisition. At about the same cost as acquiring ROW and moving utilities, this concept greatly reduced the time required for project completion and the need to disrupt the front yards of homes along Piper Road. Existing, significant trees also did not need to be removed. Existing water and sanitary sewer main lines and services were either protected or replaced to accommodate the new storm sewers. We leveraged our relationship with CenterPoint Energy to expedite relocations with the proposed storm sewer before construction began, keeping the project on schedule. The project significantly improved drainage compared to the existing roadway ditches. At a Glance 2,900 Feet $1.2 million Construction Cost Markets Municipal Services Water & wastewater

Cedar Bayou Crossing Corridor Study

Cedar Bayou Crossing Corridor Study Harris County and Baytown, Texas DCCM was selected to provide professional services for the proposed Cedar Bayou crossing. The crossing will serve as a critical link for the City of Baytown to ensure the orderly development of the northern part of the city and provide necessary east-to-west mobility to supplement IH 10. The project area was from Hunt Road at Main Street to Kilgore Parkway at SH 146. DCCM provided project management, data collection, existing condition evaluation, alternative analysis, community outreach support, preliminary engineering, geotechnical investigation, subsurface utility engineering, survey, and an environmental analysis. DCCM conducted a corridor study to identify alignment alternatives and assess the project’s feasibility. The study included several aspects to consider and required sufficient information to measure and evaluate a range of viable improvement options. The traffic analysis reviewed traffic and crash data, existing roadways, traffic flow patterns, traffic counts, turning movement counts, and transit and traffic operations. The DCCM team conducted capacity analyses for designated locations and sections of roadways and made recommendations to improve traffic flow. DCCM provided hydrology and hydraulics to support the corridor layout of the proposed roadway. This task used the latest Mapping, Assessment, and Awareness project (MAAPNext) models for Cedar Bayou as developed by the Harris County Flood Control District. DCCM also provided community outreach, public meetings, and City Council meetings. The project concluded with identifying recommended improvements, preliminary plans with several alternatives and their estimated costs, and a preferred alignment. Surveying Services DCCM performed professional surveying services to obtain and review existing lidar data and the limited preliminary ground survey data for the Cedar Bayou Corridor Study. The project spanned 3.7 miles from North Main Street, 3,300 feet south of IH 10 (west tie-in point), to the intersection of SH 146 and Kilgore Parkway (east tie-in point). The latest available lidar data published from USACE and Texas Natural Resources Information System covering the project area to evaluate and perform the following tasks: Data sets were extracted/downloaded into Esri ArcGIS (Pro+3D Analyst tool) and Context Capture/OpenRoads Cross-data checks were performed against public datasets from TxDOT, the City of Baytown, Harris County, and other available online resources. The MicroStation DGN deliverable included: DEM 2D building/structure footprints Roads, highways, and railroads Overhead transmission lines Other visible features within the lidar data Limited field surveying was performed. Field surveying tasks included setting four project control points, performing limited topographic surveying along North Main Street (1,000 feet north and south of the west tie-in point) and SH 146 (500 feet north and south of the west tie-in), and obtaining cross sections along the existing railroad running through the project. Field surveying also included determining the elevations of the existing railroad running at the railroad bridge over SH 146 and confirming (spot-checking) the lidar data in several accessible areas. The survey data was based on the NAD 83, Texas Coordinate System, South Central Zone (4204) CORS adjustment. Elevations were based on the NAVD 88 2001 adjustment relative to the lidar data. The survey information was provided in MicroStation Select Series 10. At a Glance 3.7 Miles $140 million Construction Cost Markets Transportation Surveying Services Transportation Surveying Utilities Water & Wastewater