Mason Valley Groundwater Model: Linking Surface Water and Groundwater in the Walker River Basin, Nevada¹

Abstract

Carroll, Rosemary W.H., Greg Pohll, David McGraw, Chris Garner, Anna Knust, Doug Boyle, Tim Minor, Scott Bassett, and Karl Pohlmann, 2010. Mason Valley Groundwater Model: Linking Surface Water and Groundwater in the Walker River Basin, Nevada. Journal of the American Water Resources Association (JAWRA) 46(3):554‐573. DOI: http://dx.doi.org/10.1111/j.1752-1688.2010.00434.x Abstract: An integrated surface water and groundwater model of Mason Valley, Nevada is constructed to replicate the movement of water throughout the different components of the demand side of water resources in the Walker River system. The Mason Valley groundwater surface water model (MVGSM) couples the river/drain network with agricultural demand areas and the groundwater system using MODFLOW, MODFLOW’s streamflow routing package, as well as a surface water linking algorithm developed for the project. The MVGSM is capable of simulating complex feedback mechanisms between the groundwater and surface water system that is not dependent on linearity among the related variables. The spatial scale captures important hydrologic components while the monthly stress periods allow for seasonal evaluation. A simulation spanning an 11‐year record shows the methodology is robust under diverse climatic conditions. The basin‐wide modeling approach predicts a river system generally gaining during the summer irrigation period but losing during winter months and extended periods of drought. River losses to the groundwater system approach 25% of the river’s annual budget. Reducing diversions to hydrologic response units will increase river flows exiting the model domain, but also has the potential to increase losses from the river to groundwater storage.

Managed aquifer recharge through off‐season irrigation in agricultural regions

“…A promising approach toward enhancing recharge to aquifers that has not been explored formally in the literature, is to develop MAR projects within agricultural lands during periods of excess surface water, referred to herein as Ag‐MAR. This concept hinges on the fact that many agricultural lands have historically provided significant aquifer recharge due to inefficient irrigation systems (i.e., seepage through unlined delivery canals and deep drainage beneath irrigated fields) [ Perry , ; Carroll et al ., ; Niswonger et al ., ; Scanlon et al ., ]. In agricultural lands, information about MAR suitability is generally well known by growers in the form of irrigation inefficiencies, also known as groundwater return flows, that reflect the amount of water that is lost to deep percolation or aquifer recharge relative to the amount of runoff and evapotranspiration (ET) by crop tail‐water [ Kruse , ].…”

“…Another approach for developing MAR suitability information specific to infrastructure needs is to focus on areas where recharge occurs naturally. In semiarid regions, focused recharge occurs beneath ephemeral streambeds, flood protection basins, irrigation delivery canals, and irrigated fields [ Ghayoumian et al ., ; Niswonger et al ., ; Stonestrom et al ., ; Perry , ; Carroll et al ., ].…”

Groundwater—Surface Water Interactions in a Mountain-to-Coast Watershed: Effects of Climate Change and Human Stressors

“…Coupled groundwater-surface water models are being increasingly used to examine a variety of environmental interactions, including interactions in small mountainous catchments [6]; solute transport [7,8], flood wave modeling [9], catchment water resource management and understanding [10][11][12][13][14][15][16][17], the role of aquifer heterogeneity [18,19], and wetland alterations and aquaculture [20,21].…”

A hydro-environmental watershed model improved in canal-aquifer water exchange process

“…In agricultural lowland area, drainage canals play an important role in groundwater discharge from shallow aquifers to keep soil water contents proper in crop fields. Carroll et al (2010) developed a MODFLOW-based hydrological model in which the water exchange between drainage canals and aquifer is focused on but the canal flow is assumed to be steady and uniform. Takeuchi et al (2009) developed a finite-volume hydro-environmental model in which the water exchange between drainage canals and aquifer is taken into account.…”