At HDR, our employee-owners are fully engaged in creating a welcoming environment where each of us is valued and respected, a place where everyone is empowered to bring their authentic selves and novel ideas to work every day. As we foster a culture of inclusion throughout our company and within our communities, we constantly ask ourselves: What is our impact on the world?Watch Our Story: believe water is more than a resource, it's a shared responsibility. As part of our Water Business Group, you'll help shape how communities manage water for generations to come. From delivering safe drinking water and treating wastewater responsibly to developing sustainable water supplies and protecting lives and property through flood control, your work will directly support public health, environmental sustainability, and infrastructure resilience. We bring together experts across disciplines to solve complex challenges with bold thinking and technical excellence. Whether you're modernizing aging systems or pioneering innovative approaches, your contributions will make a meaningful difference in people's lives. This isn't just a job, it's a chance to lead change, drive progress, and leave a lasting legacy.Each and every role throughout our organization makes a difference in our ability to change the world for the better. Read further to learn how you could help make great things possible not only in your community, but around the world.This position is well-suited for an experienced water resources professional with a strong technical foundation and increasing responsibility in project delivery, client interaction, and technical leadership. The ideal candidate will bring depth in reservoir system operations, hydrologic and hydraulic modeling, watershed hydrology, and climate change analysis, and will contribute meaningfully to team leadership and mentoring.Our clients include local, state, and federal agencies, and our work spans some of the most complex and high-profile water resources challenges in California and the western U.S. The selected candidate will play a key role in project execution, staff development, and the delivery of high-quality technical work across a diverse portfolio.Skills such as scripting (e.g., WRESL, Python/Jython, or VBA) and experience with CalSim II and CalSim 3, CalLite, VIC, HEC software (HEC-SSP, HEC-HMS, HEC-ResSim and both HEC-RAS 1D and 2D), water temperature modeling (HEC-5Q, CE QUAL W2), climate change analytical tools and datasets (e.g., Global Circulation Models and downscaling methods), linear programming and optimization would be considered beneficial.The candidate is expected to be a key part of project delivery teams; mentor junior staff; manage small- to medium-sized projects; and effectively interact with clients and peers. Candidates should be able to work independently but also enjoy working in a collaborative team environment. The candidate must have strong writing skills and good quality control/quality assurance processes.In the role of Water Resources Engineer – Modeler, we'll count on you to:Provide advanced technical support and task leadership on water resources projects related to:Water supply and reservoir operations modelingHydrology development and analysisReservoir simulation, optimization, re-operation, and decision supportHydrologic and climate change modeling, including ensemble and statistical analysesFlood risk management, FERC relicensing, and ecological enhancement projectsContribute to and, where appropriate, lead technical tasks within multi-disciplinary project teamsSupport project management activities for small- to medium-sized projects, including scope, schedule, and budget trackingMentor junior staff and support knowledge transfer, technical review, and staff developmentParticipate in client coordination, including technical meetings, work sessions, and preparation of client-facing deliverablesApply strong QA/QC practices, ensuring clear documentation, reproducible analyses, and high-quality deliverablesContribute to the development and improvement of HDR's technical tools, workflows, and best practicesProvide project engineering and task management, conduct difficult to complex hydraulic and hydrologic modeling; conduct stormwater collection systems modeling and design; collect, assimilate and present data in reports, memos and public forums; lead production of design calculations and technical reports; and lead preparation of engineering plans and specifications for design of detention facilities, storm drains, flood control facilities and other hydraulic structuresWork independently in addition to planning, organizing and assisting groups of medium to large teams of professionals and technicians dependent on project/taskConduct water resources planning, plan formulation and concept development, and develop planning documentationAssist in water resources permitting effortsPerform other duties as neededPreferred Qualifications5 or more years of experienceExperience with water infrastructure planning studies, extreme hydrology, and/or consequence analysisExperience with water supply operations modeling such as CalSim and CalLiteExperience with climate change analytical tools and datasetsExperience with reservoir and system modelingExperience with water temperature and water quality modeling (e.g., HEC-5Q, CE-QUAL-W2)Experience with risk-based planning and risk-informed decision makingFamiliarity with integration of resiliency into the planning processLinear programming, optimization, and decision-support modelingScripting and automation using Python/Jython, WRESL, VBA, or similar toolsFamiliarity with NEPA and ESA processes, including supporting environmental compliance, biological assessments, effects analyses, and coordination with environmental and regulatory teamsRequired QualificationsBachelor's degree in Engineering or equivalent fieldPrevious experience in water resources engineering projectsRequires professional engineering license recognized by the licensing board for the location of the position offered. Example: Professional Engineer (PE or P.Eng) license.Excellent oral and written communication skillsAn attitude and commitment to being an active participant of our employee-owned culture is a mustWhat We Believe HDR is our company. Together, we build on each other's life experiences and perspectives to make great things possible every day. This shapes our collaborative culture, encourages organizational trust and connects us closer to the clients and communities we serve.Our Commitment As employee owners, we all have a role in creating an inclusive environment where each of us is welcomed, valued, respected and empowered to bring our authentic selves to work every day.Our eight Employee Network Groups (Asian Pacific, Black, Hispanic/Latino(a), LGBTQ+, People with Disabilities, Veterans, Women, Young Professionals) help create a sense of belonging and foster a supportive environment where everyone is empowered to engage and contribute. Each group has an executive sponsor and is open to all employees.Locations & Schedule Primary Location : California, USAIndustry : WaterSchedule : Full-timeEmployee Status : RegularBusiness Class: Water Supply ManagementJob Posting : Jan 21, 2026Equal Opportunity HDR is committed to the principles of employment equity. We are an Affirmative Action and Equal Opportunity Employer. We consider all qualified applicants, regardless of criminal histories, arrest and conviction records.Ready to learn more? Let's work together to make great things possible. We design solutions to the world's greatest challenges. We're always looking for great talent to join our global teams.#J-18808-Ljbffr