Science Module: Environmental Flows and Water Security
Today’s rivers experience a wide variety of anthropogenic stressors. Roads, rooftops and development in our urbanized areas cause increased runoff and reduced recharge for groundwater, while numerous dams, reservoirs, and water withdrawals, alter our rivers natural flow regimes. A changing climate has added weather extremes such as increased flooding and droughts, bringing uncertainty to the field of water resources management. Changes in river flows impact the chemical, physical and biological aspects of our rivers, and hydrologic alteration has been recognized as a cause for failing to meet designated uses for aquatic life under the Clean Water Act.
To better understand the impacts of these threats, and seek to protect and restore natural flow regimes that provide benefits for people and wildlife, several key science and management approaches have been developed in recent years.
Purpose of this Science Module
This science module will introduce you to the concepts of water budgets, environmental flows, and water security and provide instruction on using tools that are now available online. We’ve assembled already available resources from our partners in the field of ample water, and produced new material to help weave together these concepts and introduce new resources.
The segments may be watched individually but are intended to be watched in sequence so they may build upon each other for greatest understanding. After watching the module, if you have any questions about the material, or are interested in learning more about how you might see these types of projects pursued in your watershed, please feel free to contact our Science Manager, Adam Griggs. You may also access the videos on our Youtube channel here.
Begin Science Module
Navigate through the 5-part module using the tabs below.
Fundamental Concepts of Environmental Flows
Video 1: A segment from the documentary movie Sense and Sustainability
This short video helps set the tone for examining human impact on river ecosystems. Brian Richter (The Nature Conservancy and River Network Board Member) gets you thinking about rivers and their natural flows and the unique ecological services and niches they provide.
Fundamental Concepts of Environmental Flows
Video 2: Understanding environmental flows
Brian Richter (The Nature Conservancy and River Network Board Member) introduces the science of environmental flows, how ecological services are accounted for and how alteration to hydrologic cycles can be measured and tied to the health of aquatic life.
Tools for Investigating Environmental Flows
Video 3: Environmental flow tools from the National Water Census Data Resources Portal
Dave Blodgett (Project Manager for the USGS Water Census Data Resources Portal) walks us through the resources available for investigating environmental flows in your watershed, available through the portal. From accessing real-time and historic flow data, to calculating flow statistics and indicators of hydrologic alteration, or downloading modeled baseline flow hydrologies for un-gaged watersheds., this new tool will surely prove useful for anyone looking to explore flow conditions in their watershed.
Fundamental Concepts of Water Budgets
Video 4: Introduction to water budgets for water security
Water budgets are a strict accounting of water in, though, and out of a closed system. From precipitation rates to evapotranspiration and consumptive use, the water moving through your watershed can be accounted for and help with planning to meet future water needs. Brian Richter (The Nature Conservancy, Board Member of River Network) introduces the concept of water budgets, explains how they are calculated, and how the information can be used to enhance water security and instream flows.
Tools and Data for Constructing Water Budgets
Video 5: Water budget data tools from the National Water Census Data Resources Portal
Dave Blodgett (Project Manager for the USGS Water Census Data Resources Portal) shows us how to access flow, water-use, precipitation, and evapotranspiration data to contribute to a water budget for your watershed.
Additional Resources for Pursuing Environmental or Ecological Flows Projects
- Instream Flow Council
- Southern Instream Flow Network and Flow Protection Policy Overview Introduction Report by Southeast Aquatic Resources Partnership (SARP)
- Environmental Flow Components by The Nature Conservancy
- A Practical Guide to Environmental Flows for Policy and Planning by the Nature Conservancy
- Understanding Climate Change Impacts on Water Resources by U.S. EPA
- Ecological Limits of Hydrologic Alteration by The Nature Conservancy
- Indicators of Hydrologic Alteration by The Nature Conservancy