Water security refers to a water resource’s acceptable level of water-related risk while satisfying the need for livelihood, human well-being, and ecosystem functioning. Water security is vital in socio-economic development, ecosystem management, and environmental sustainability. Over the last four decades, water security assessment has attracted much political and economic attention. Our team focuses on an improved understanding of the relationships between water demand and supply to mitigate the impacts of diminishing water resources. We apply the water footprint concept (blue, green, and grey) to quantify the water security of different sectors (e.g., agriculture) at different resolutions. Various hydrological models, such as the Soil and Water Assessment Tool (SWAT), are applied to quantify regional water security. We are monitoring the water quality of wetland pond ecosystems that receive runoff water from agricultural row crops (vegetable) and pasture operations.