Our Team
A. Jake Gusman P.E., BC.WRE
Jake is a senior water resources engineer and project manager based in Southern California with over 28 years of experience. His expertise includes hydraulic modeling, floodplain studies, hydrology, bridge scour analysis and countermeasures, and stream restoration. He has led numerous FEMA map revision projects in Hawaii and California and managed U.S. Army Corps of Engineers task orders across the western U.S.
Darren J. Bertrand, CFM
Darren is a senior hydrologist and hydraulic modeler based in Southern California with over 23 years of experience. He specializes in hydrologic and hydraulic modeling, 2D floodplain studies, dam break analysis, levee certification, and flood forecasting systems. He has worked with clients at all levels of government on a wide range of water resource projects.
Blake Biethman, P.E.
Blake is a water resources engineer based in Nevada with over 5 years of experience. He has worked in both the public and private sector on projects across the western U.S., and specializes in 1D and 2D hydraulic modeling, fish passage design, and geomorphic assessments. Prior to joining River Focus, Blake worked for the Bureau of Reclamation in Colorado.
Holly Callahan, P.E., CFM
Holly is a water resources engineer based in Southern California with over 7 years of experience in both the public and private sector. Her expertise includes hydrology and 1D/2D hydraulic modeling for fish passage, bridge replacements, and flood studies, bridge scour and scour countermeasure analyses, and FEMA floodplain mapping and map revisions.
Evie Croft, EIT
Evie is a water resources engineer based in Southern California with over 9 years of experience. Her work focuses on stormwater design, 1D and 2D hydraulic modeling, hydrologic analysis, and floodplain studies. She has contributed to projects involving FEMA map revisions, landfill and groundwater design, water quality analysis, and environmental monitoring.
Sydney Doidge, P.E.
Sydney is a water resources engineer based in Southern California with over 5 years of experience. She specializes in hydrologic analysis and 1D/2D hydraulic modeling, with a focus on bridge and culvert replacement projects across the U.S. She is also a certified Part 107 drone pilot.
Grant Doty, EIT
Grant is a water resources engineer based in Northern California with over 4 years of experience. His background includes public sector work in data integration, water use reporting, and community engagement. His technical skills include hydraulic and hydrologic modeling, GIS, bridge scour analysis, programming, and data visualization.
Henry Doyle, EIT
Henry is a water resources engineer based in Southern California with over 5 years of experience. His work in the public sector includes hydraulic and hydrologic modeling for stormwater systems and invasive species mitigation in the Great Lakes. His background includes laboratory research on fish egg capture, as well as skills in GIS, programming, and project management.
Grant Graves
Grant is a senior hydrologist based in Oklahoma with over 13 years of experience. His background includes public-sector research and consulting work focused on watershed modeling, stormwater management, and water-quality assessment. His technical skills include H&H and stormwater modeling, GIS, applied research and assessment methods for contaminant transport and water-quality analysis, and advanced data analytics.
Brady Halvorson, EIT
Brady is a water resources engineer based in Hawaii with over 4 years of experience. His expertise includes floodplain management, H&H modeling, drainage design, and FEMA mapping. He has worked on projects involving stormwater management, channel restoration, and groundwater treatment. He is also pursuing a PhD in coastal engineering at the University of Hawai‘i at Mānoa.
Tyler Hileman, EIT
Tyler is a water resources engineer based in Pennsylvania with over 5 years of experience. He specializes in hydrologic and hydraulic analysis, construction oversight, and GIS mapping. He has led efforts in data acquisition, design, and monitoring for projects involving bank stabilization, culvert replacement, and bridge installation.
Peter Kickham
Peter is a water resources engineer based in Northern California with 2 years of experience. He specializes in hydraulic modeling using HEC-RAS and SRH-2D and has focused on bridge scour analysis. His master’s research explored modeling methods for scour analysis, and he has contributed to tool development and GIS-based data collection.
Bryce Sattenspiel, EIT
Bryce is a water resources engineer based in Oregon with 1.5 years of experience. HIs work in both the public and private sectors include hydrologic and hydraulic analyses and hands-on field-based river restoration. Prior to joining River Focus, Bryce worked for the Natural Resources Conservation Service (NRCS).
Jess Straub
Jess is a habitat restoration engineer and project manager based in Alaska with over 6 years of experience. She has worked extensively on stream and river studies across Alaska, focusing on surveying, mapping, and floodplain analysis. Her background includes project management, hydraulic modeling, and AutoCAD Civil 3D design.
Katy Thompson, P.E., CFM
Katy is a senior civil and water resources engineer based in Minnesota with over 22 years of experience, working in the public and private sectors across the United States and Canada. She specializes in practical solutions to complex water resources using her background in hydrologic, hydraulic, and water quality modeling and construction design and contract management.
Vicki Tripolitis
Vicki is a senior hydraulic engineer based in Southern California with over 25 years of experience. She specializes in 1D/2D hydraulic modeling, floodplain studies, dam and levee breach analysis, sediment transport, and channel design. She previously served as a senior hydraulic engineer with the U.S. Army Corps of Engineers.
Jon Viducich, P.E.
Jon is a senior hydraulic engineer and assistant project manager based in Southern California with over 17 years of experience. He has worked globally on complex water resource projects involving hydrologic, hydraulic, and sediment transport modeling. He also teaches as an adjunct professor and consults for international development organizations.