Billy E. Johnson, PHD, PE, D.WRE, FASCE, is a Senior Scientist at LimnoTech. Billy has over 40 years of experience as a civil research engineer, educator, and consultant for projects across the U.S. He has a broad range of expertise in water resources, including successful leadership of projects involving developing and applying hydraulics, hydrology, sediment, nutrient, contaminant, and riparian vegetation simulation models for civil works and military projects. These models have been integrated with various U.S. Army Corps of Engineers (USACE) hydraulic and hydrologic (H&H) modeling systems (e.g., GSSHA, HEC-RAS, HEC-HMS, HEC-RESSIM, AdH).
Billy is working with Limno Tech and USACE to develop the Clearwater Riverine Water Quality Library to provide nutrient, contaminant, water quality, and ecosystem capabilities to USACE H&H modeling systems. This library is being linked to the Clearwater-2D transport model, which is being developed to incorporate computational domains and hydraulic/sediment fluxes from disparate H&H modeling systems. The first H&H model to take advantage of these fate and transport capabilities is the Hydrologic Engineer Center River Analysis System (HEC-RAS-2D). These enhanced modeling systems are the backbone of predictive modeling capabilities for USACE’s Engineering With Nature (EWN) focus area for planning and engineering design of Nature-Based Solutions (NBS) within USACE projects.
As models are being asked to solve more complex water and environmental problems, it has become necessary to integrate and link legacy models not originally intended for a particular purpose. Billy is working with federal, university, and private sector teams to integrate landscape and waterbody models to simulate flows, sediment, water quality, and ecosystem services on small temporal and spatial scales as well as large basin and long-term scales. These integrated modeling systems are being developed to solve problems associated with wildfires and harmful algal blooms (HABs) to perform flow, mobility, and contaminant fate issues associated with operational warfighter deployments.
In addition to creating linked modeling systems to solve HABs problems, Billy is working with engineers and scientists to provide better process descriptions within the USACE 2D reservoir modeling system (CEQUAL-W2). Some of these improvements involve more accurate simulation of toxin generation, better buoyance routines for organic particulate matter, and more accurate estimates of nitrogen fixation.
Billy is working with DoD and Limno Tech engineers and scientists to develop radionuclide fate and transport capabilities for the gridded surface subsurface hydrologic analysis (GSSHA) model. These new capabilities will provide overland and stream fate and transport of radionuclides to enhance DoD’s ability to ensure nuclear treaty compliance and develop mitigation strategies for contaminated environments. In addition, Billy has also been involved in developing U.S. Army Installation Energy and Water Plans (IEWP), Flood Mapping and Mitigation Plans for Overseas DoD Installations in data-poor regions, and Low Impact Development (LID)/Nature-Based Features projects for DoD installations.
Billy previously served as a senior researcher at the U.S. Army Engineer Research and Development Center (ERDC), Environmental Laboratory (EL). In addition to working for EL, he also worked for the ERDC Coastal and Hydraulics Laboratory (CHL) and the Memphis District USACE. He was an adjunct faculty member at Mississippi State University and was an Associate Editor of the Journal for the American Water Resources Association (JAWRA).
Billy currently resides and works in Vicksburg, Mississippi.
Tel: 601-415-6299
