What We Do
Hydrologic modeling
Hydrologic models are conceptual mathematical representations of select parts of the hydrologic cycle. RCD models stream systems to better understand hydrologic processes by predicting the response of a system or element of a system (stream, drainage network, aquifer, reservoir, etc) to various scenarios (100-year storm, conversion of woodland to vineyard, etc.).
Napa River Model
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Unsteady flow hydraulic model developed using the MIKE 11 software from DHI Water and Environment.
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Able to track the progress over time and space of floods, tidal events, and interactions between the two, within the limits of a network of one-dimensional channels.
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Developed in phases beginning in 1995. Includes the Napa River mainstem from Kimball Reservoir to the Mare Island Causeway, as well as Garnett and Hopper Creeks.
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In 1999, a rainfall-runoff model was added using the MIKE 11 rainfall-runoff module.
Integrated Hydrologic Modeling
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All processes of the hydrologic cycle are dynamically linked. Rainfall infiltrates the soil to recharge groundwater and also runs off as stream flow. In certain reaches, or times of the year, streamflow infiltrates through its bed to recharge groundwater, and at other times groundwater seeps into channels producing flow in the dry season. Urbanization and agriculture reduce infiltration and direct more stormwater to stream channels.
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An integrated hydrologic model dynamically links surface and groundwater models to allow a complete representation of the hydrologic system.
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DHI Water and Environment developed an integrated surface-groundwater model using MIKE SHE (a DHI software product) for Napa County’s Baseline Data Report (BDR).
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RCD used the BDR model to develop a MIKE SHE model of Carneros Creek (Water for Fish and Farms project). A MIKE SHE model of Redwood Creek is in progress.
HEC Models
The US Army Corps of Engineers Hydrologic Engineering Center (HEC) has developed a suite of software products for modeling applications that are widely used and accepted by hydrologists.
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HEC-HMS: Simulation of rainfall-runoff processes. In recent years, RCD has performed HEC-HMS analyses of Tulucay, Napa, and Salvador Creeks to predict streamflows in ungaged streams or to evaluate land use changes (including vineyard developments).
