University of California

AgMAR / FloodMAR

Agricultural Managed Aquifer Recharge (AgMAR) / Flood MAR

The 2014 Sustainable Groundwater Management Act requires groundwater basins with significant overdraft, land subsidence, seawater intrusion, water quality degradation, or groundwater pumping induced reduction in streamflow to develop sustainable groundwater management practices. Managed aquifer recharge is an important tool to capture winter runoff not currently allocated to water users and in excess of instream flow requirements. We have partnered with colleagues at UC Davis and UC Water, and with the Public Policy Institute of California to implement cutting edge research.  The work significantly supports sound future decision making by water management districts, reservoir operators, state agencies (including water rights division) to increase the amount of managed aquifer recharge using California’s large agricultural landscape as a venue.

Agricultural managed aquifer recharge may include winter irrigations in various forms, recharge through unlined canals and set aside land (recharge basins), in lieu recharge, and other forms. Evaluation of water quality implications are another important research topic as these may include threats from flushing of legacy contamination but also benefits by increasing the amount of clean water recharge into potentially contaminated groundwater. We are developing several assessment and modeling tools to evaluate potential increases in groundwater recharge that may be realized, to address water quality issues, but also to understand potential improvements in groundwater-surface water interactions resulting from additional recharge.

Relevant Publications:

Castaldo, G., A. Visser, G.E. Fogg, T. Harter, 2021. Effect of groundwater age and recharge source on nitrate concentrations in domestic wells in the San Joaquin Valley. Env. Sci. Technol. 55(4):2265-2275, doi:10.1021/acs.est.0c03071

Waterhouse H., T. Broadhead, A. Massell, H. Dahlke, T. Harter, D. Mountjoy, 2021. Management considerations for protecting groundwater quality under agricultural managed aquifer recharge. Sustainable Conservation, Research Brief and Guidance

Escriva-Bou, A., R. Hui, S. Maples, J. Medellin-Azuara, T. Harter, J.R. Lund, 2020. Planning for groundwater sustainability accounting for uncertainty and costs: An application to California's Central Valley, J. Environ. Management, doi:10.1016/j.jenvman.2020.110426

Kourakos, G., H.E. Dahlke, T. Harter, 2019. Increasing groundwater availability and seasonal baseflow through agricultural managed aquifer recharge in an irrigated basin. Water Resour. Res., doi:10.1029/2018WR024019 (open access)

Ghasemizade, M., K.O. Asante, C. Petersen, T. Kocis, H.E. Dahlke, and T. Harter, 2019. An integrated approach toward sustainability via groundwater banking in the southern Central Valley, California. Water Resources Research, 55. doi:10.1029/2018WR024069. (pdf file for personal use only)

Hanak, E., A. Escriva-Bou, B. Gray, S. Green, T. Harter, J. Jezdimirovic, J.R. Lund, J. Medellín-Azuara, P. Moyle, N. Seavy. 2019. Water and the Future of the San Joaquin Valley. Final Report, Public Policy Institute of California, San Francisco, California, 100 p. (open access)

Mount, J., E. Hanak et al., 2018. Managing Drought in a Changing Climate: Four Essential Reforms. Public Policy Institute of California Report, 30 p.

Edwards, E. C., Harter, T., Fogg, G. E., Washburn, B., & Hamad, H. 2016. Assessing the Effectiveness of Drywells as Tools for Stormwater Management and Aquifer Recharge and Their Groundwater Contamination Potential. Journal of Hydrology 539:539-553, doi:10.1016/j.jhydrol.2016.05.059.

Harter, T., 2015. California's agricultural regions gear up to actively manage groundwater use and protection. California Agriculture 69(3):193-201, doi:10.3733/ca.E.v069n03p193 (open access)

O'Geen, T., M.B.B. Saal, H.E. Dahlke, D.A. Doll, R.B. Elkins, A. Fulton, G.E. Fogg, T. Harter, J.W. Hopmans, C. Ingels, F.J. Niederholzer, S. Sandoval-Solis, P.S. Verdegaal, M. Walkinshaw, 2015. Soil suitability index identifies potential areas for groundwater banking on agricultural lands. California Agriculture 69(2):75-84, doi: 10.3733/ca.v069n02p75 (open access).

Mayzelle, M. M., J. H. Viers, J. Medellin-Azuara, and T. Harter, 2015. Economic feasibility of irrigated agricultural land use buffers to reduce groundwater nitrate in rural drinking water sources. Water 7(1):12-37, doi: 10.3390/w7010012 (open access).

Harter, T. and H. Dahlke, 2014. Out of sight, but not out of mind: California refocuses on groundwater. California Agriculture 68(3):54-55. doi:10.3733/ca.v068n03p54 (open access).

Kourakos, G. and T. Harter, 2014. Vectorized simulation of groundwater flow and streamline transport. Environmental Modelling & Software 52:207-221, doi:10.1016/j.envsoft.2013.10.029.

Marques. G. F., J. R. Lund, M. R. Leu, M. Jenkins, R. Howitt, T. Harter, S. Hatchett, N. Ruud, and S. Burke, 2006. Economically driven simulation of regional water systems: Friant-Kern, California. J. Water Resour. Planning and Mgmt 132(6):468-479. DOI: 10.1061/(ASCE)0733-9496(2006)132:6(468).

Ruud, N. C., T. Harter, and A. W. Naugle, 2004. Estimation of groundwater pumping as closure to the water balance of a semi-arid irrigated agricultural basin. J. Hydrology 297:51-73. (pdf file for personal use only)

Independent Panel on Appropriate Measurement of Agricultural Water Use, Convened by the California Bay-Delta Authority, Final Report, September 2003.

Ruud, N. C., T. Harter, A. W. Naugle, 2002. A conjunctive use model for the Tule groundwater sub-basin area in the Southern-Eastern San Joaquin Valley, California, Final Report to the U.S. Bureau of Reclamation, November 2002, 196 pages. (pdf file for personal use only)

Ruud, N. C., T. Harter, A. W. Naugle, 2002. A conjunctive use groundwater-surface water flow model for the Tule River groundwater basin in the eastern-central San Joaquin Valley, California; in: Marino, M. A. & S. P. Simonovic, Integrated Water Resources Management, IAHS Publication No. 272, pp. 167-174.

Ruud, N. C., T. Harter, 2000. Conditional geostatistical model of alluvial hydrofacies for risk analysis of deep groundwater quality deterioration from shallow salinity, Post-Conference Proceedings, International Conference on Calibration and Reliability in Groundwater Modeling, Zuerich, Switzerland, 20-23 Sept. 1999, IAHS Publication No. 265, Oxfordshire, UK.

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