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Monitoring data from a managed aquifer recharge system that collects stormwater runoff in central coastal California. Precipitation, runoff, infiltration, sediment, survey

Cite this collection

Beganskas, Sarah; Fisher, Andrew (2016). Monitoring data from a managed aquifer recharge system that collects stormwater runoff in central coastal California. Precipitation, runoff, infiltration, sediment, survey [Collection]. Dryad. https://doi.org/10.7291/D13W28

Abstract

Groundwater is increasingly important for satisfying California’s growing fresh water demand. Strategies like managed aquifer recharge (MAR) can improve groundwater supplies, mitigating the negative consequences of persistent groundwater overdraft. Distributed stormwater collection (DSC) MAR projects collect and infiltrate excess hillslope runoff before it reaches a stream, focusing on 40–400 ha drainage areas (100–1000 ac). We present results from six years of DSC–MAR operation—including high resolution analyses of precipitation, runoff generation, infiltration, and sediment transport—and discuss their implications for regional resource management. This project generated significant water supply benefit over six years, including an extended regional drought, collecting and infiltrating 5.3 × 105 m3 (426 ac-ft). Runoff generation was highly sensitive to sub-daily storm frequency, duration, and intensity, and a single intense storm often accounted for a large fraction of annual runoff. Observed infiltration rates varied widely in space and time. The basin-average infiltration rate during storms was 1–3 m/d, with point-specific rates up to 8 m/d. Despite efforts to limit sediment load, 8.2 × 105 kg of fine-grained sediment accumulated in the infiltration basin over three years, likely reducing soil infiltration capacity. Periodic removal of accumulated material, better source control, and/or improved sediment detention could mitigate this effect in the future. Regional soil analyses can maximize DSC–MAR benefits by identifying high-infiltration-capacity features and characterizing upland sediment sources. A regional network of DSC–MAR projects could increase groundwater supplies, while contributing to improved groundwater quality, flood mitigation, and stakeholder engagement.

Funding

University of California Water Security and Sustainability Research Initiative, Award: #449214-RB-69085

California Institute for Water Resources, Award: #SA7750

National Science Foundation

Charles and Jennifer Lawson Hydrology Awards

John Mason Clarke 1877 Fellowship, Amherst College