Water Resources

Trihydro personnel have substantial experience with water rights and water resource administration. Trihydro is experienced in evaluating water rights based on priorities, diversion records, and water usage. We have also assisted clients with inventory, evaluations, and modifications of their water rights to manage risks and obtain goals. Our experience includes providing surveying services for plan preparation, coordinating with local and state agencies, and developing strategic plans for the management of surface, spring, and groundwater rights.

Trihydro is also experienced in navigating state and federal permit requirements associated with various agencies such as:

• U.S. Army Corps of Engineers (USACE). Under Section 404 of the Clean Water Act (CWA), activities such as water resources projects (e.g. dam construction), mining projects, stream restoration, and infrastructure developments require a permit before dredged or fill materials can be discharged into special aquatic resources, wetlands or “waters of the United States.” Trihydro has experience assisting with individual and nationwide permit identification, coordination with local Divisions, implementation of permit-specific tools such as the Stream Quantification Tool (SQT), and stream and wetland mitigation.
• Federal Emergency Management Agency (FEMA). Trihydro personnel are routinely involved in conducting analyses to delineate flood hazard areas, assessing impacts of proposed development on floodplains, and mapping flood hazards. Permitting services include FEMA No-Rise Certification, CLOMR, LOMR & LOMAs.
• U.S. Environmental Protection Agency (EPA). Under the CWA, EPA authorizes the NPDES permit program to state, tribal, and territorial governments. Trihydro works with the specific entity to permit and reduce stormwater runoff and improve water quality on projects.

As a national firm, we have experience with permitting requirements in numerous states and routinely assist clients with stormwater, discharge, floodplain, groundwater, and water use permits specific to a given area.

As experts in hydrologic and hydraulic modeling, we utilize a wide variety of existing modeling packages. Our experience includes the development and application of hydrologic models (HEC-HMS, HSPF, SAC-SMA, SNOW-17, TR-55 methods, etc.), hydraulic models (1-D and 2-D HEC-RAS, FLO-2D, etc.), and reservoir operations models (HEC-ResSim, RES-J, etc.). We also develop customized modeling applications, supported by our software development team, to meet specific user needs. In addition to surface hydrology and hydraulics applications, we have expertise in groundwater flow (MODFLOW) and contaminant transport (MT3DMS) models, as well as models that simulate groundwater-surface water interaction (GSFLOW).

Our modeling process includes working with clients to define objectives, collecting and analyzing relevant hydrometeorological and system data, formulating the conceptual model, selecting the appropriate model application or programming platform, developing the model utilizing the collected datasets and selected application, calibrating and verifying the developed model using historical events, and applying the developed model to achieve the defined objectives.

Our experts also incorporate developed models into customized decision support frameworks (HEC-CWMS, HEC-RTS, HEC-WAT, Delft FEWS, etc.) to assist clients with both real-time and long-range forecasting needs. Our decision support system (DSS) development includes real-time flood warning and alert systems, flood impact analysis, water supply forecasting, climate change impact analysis, and incorporation of instream flow and water quality requirements to meet environmental objectives.

Our recent work has included the application of a 2-D rain-on-mesh model (HEC-RAS 6.0) to simulate debris and sediment flows in a wildfire-affected region. We also often apply our hydrologic and hydraulic modeling capabilities to inform the design of hydraulic structures and stormwater sewer systems. Trihydro strives to enable clients to make informed decisions based on the most accurate, relevant information. To achieve this, we will work with clients to identify the appropriate models and tools to meet their project objectives.

Increasingly, groundwater sustainability is a topic of focus to help mitigate undesirable environmental impacts related to developing and using groundwater resources. Regulatory agencies develop policies to regulate and guide groundwater development to the benefit of the public. In some cases, understanding the connection between groundwater and surface water is an important component of groundwater sustainability. Groundwater sustainability may also include identifying potential aquifer vulnerability and mitigation measures for protecting groundwater. Groundwater-related work can also focus on groundwater contaminant monitoring and remediation.

Trihydro's groundwater experience includes managing and conducting geologic and hydrogeologic investigations, groundwater exploration assessments, and groundwater quality studies. Our team provides water well permitting, well siting, well design and drilling/construction specifications, well drilling and installation oversight, aquifer testing, and well rehabilitation. We have experience performing groundwater sustainability studies including groundwater/surface water interaction for small- to large-capacity wells and well systems. We have also performed aquifer vulnerability evaluations related to land development projects and Source Water Assessment and Wellhead Protection. These projects include designing engineering and administrative controls as potential mitigation measures to protect municipal groundwater supplies.

Trihydro's breadth of technical knowledge, geographic reach, and experience allow us to provide numerous surface water-related services, including:

• Dam and Reservoir Evaluation, Inspection, Design, and Permitting
• Irrigation and Hydraulic Structures
• Stream Assessment and Restoration
• Streambank Protection and Stabilization
• Riparian/Wetland Mitigation and Development
• Floodplain Management
• Stormwater Management
• Erosion Control
• Watershed Management/Implementation Plans
• Fire Response