Conjunctive Water Management Explained at WRRC Water Webinar
On Tuesday, November 18, Randall Hanson, President/Hydrologist of One-Water Hydrologic, presented a WRRC Water Webinar, titled “Conjunctive Water Management for Sustainability." Conjunctive Water Management (CWM) is a holistic approach to water management within a sustainability framework that considers all potentially available water sources. Its benefits include greater water supply security and reduced negative impacts, such as subsidence, saltwater intrusion, surface water impairment, and damage to riparian and groundwater dependent ecosystems.
Hanson provided examples of how the development of “formal” or planned monitoring and operations systems based on CRM have improved water supply outcomes. He described cases in which managed aquifer recharge of multiple source waters plays a major role in CRM and in restoring an aquifer’s dynamic equilibrium. His presentation contained several instances of aquifer system connections that can impact water supply system outcomes.
One Water’s conjunctive use modeling framework uses a version of MODFLOW, a US Geological Survey (USGS) developed model. The CWM code is open-source and freely available. The CWM model can integrate a variety of land uses and water sources relevant to the area of interest to simulate its hydrology.
One Water’s various monitoring and modeling tools can be used to create a holistic CWM sustainability framework for implementation where appropriate governance and financial support exist. The CWM approach to governance prescribes decision making and implementation authority, transparency, stakeholder participation, and institutional and technical integration.
In an effort to promote the wide adoption of CRM, the One Water Conjunctive Use Model was created for educational use. A book titled Conjunctive Water Management, co-authored by Hanson and hydrogeologist Richard Evans and published by The Groundwater Project, is available online at no charge.