The importance of natural flow regimes to the ecological integrity of rivers has been established for decades, but more specific information is needed to develop and implement scientifically credible instream flow standards. The information in this section follows the Ecological Limits of Hydrologic Alteration (ELOHA, Poff et al. 2010) framework and Southern Instream Flow Research Agenda for establishing scientifically credible relationships of ecological responses to flow alteration.

Approach:  A fundamental concept behind the Southern Instream Flow Research Agenda was the involvement of regional aquatic experts in the development and review of the instream flow resources and research plans.  An expert review committee for each resource was comprised of regional and national experts that helped ensure that the products are technically correct and achieve what was intended (See the Expert Review Process for each resource below). Once the Instream Flow Resources were developed, the aquatic experts involved in this process serve as a body of experts that are well versed in the issues of flow-ecology relationships and the supporting information that is now available for their area. They can help guide future work towards the priority research topics that will advance instream flow science in their area.

Resource Descriptions, Maps, and Supporting Data:  SARP's Instream Flow Resources are housed in two, linked locations:  here and the Conservation Planning Atlas (CPA).  The information in the following sections describes the individual products and how they were developed. Click on the "Read More" link for each instream flow resource below to go to specific information about that product.  You may also view an introductory video that explains the individual resources by clicking here.

Many of these resources are map-based and have supporting databases that can be used for further analyses.  The maps can be viewed and databases accessed through the CPA.  Instructions to access the CPAs can be found by clicking here.

Regional Flow-Ecology Hypotheses

A holistic suite of flow-ecology relationships that demonstrate ecological responses to alterations of the natural flow regimes form the scientific basis for setting ecological limits of hydrologic alteration for streams and rivers in the region. Very few of these relationships have been identified, however, which limits the ability of southern states to substantiate state instream flow standards and water management practices. Read More....

River Classification Framework

River classification has many uses. The regional classification framework presented here provides a common terminology of ecologically-relevant streamflow attributes for describing rivers across the 14-state SARP region. For the purpose of quantifying ecological responses to flow alteration, this classification framework provides information that may explain differences in responses to flow alteration in different types of rivers. Read More....

Regional Hydrologic Foundation

A primary objective of the SARP instream flow projects for the SALCC and GCPLCC is to develop baseline information on hydrologic alteration in rivers and streams across the region. Long-term water level gage data and hydrologic models can be used to estimate baseline (i.e., reference), current, and future hydrographs so that flow alerations at a location can be quantified. Changes in ecological condition can then be assessed relative to the degree of flow alteration.  Read More....

Aquatic Data

A critical step in developing instream flow standards is to demonstrate ecological responses to alterations in the flow regime. Limits to flow alterations can then be set based on acceptable levels of ecological impacts. While flow regimes can be quantified (see Regional Hydrologic Foundation above), ecological information about riverine biota, geomorphology, water quality, and other processes is widely scattered, inconsistent, and difficult to access relative to measures of flow alteration. A compilation of regional ecological data sets provides information to form and test flow-ecology hypotheses, as well as allows the identification of information gaps and development of guidelines to improve the comparability of future study results. The ecological data compilation leverages and broadens the use of local information to support stronger flow-ecology relationships across classes of rivers.  Read More...

Flow Alteration Assessment

Given the complexity of aquatic ecosystems and the myriad flow-ecology relationships, there is a need to focus limited research resources. We need to understand where ecologically significant components of the flow regime are most likely altered under common influences in the southern landscape, including water consumption, dams, and impervious surfaces.  Read More....

 Conservation Priority Areas

Our limited financial and expert resources need to be utilized where they will best meet the needs of regional aquatic resource managers. By identifying priority areas for conservation, we can focus our work on instream flows to where it will be utilized and most productive.  Read More....

 Flow Ecology Literature Compilation

As an important part of the process of developing and substantiating flow-ecology relationships, we rely on the peer-reviewed and gray literature. The flow-ecology literature can provide 1) evidence for relationships being developed using an expert-driven process, 2) quantitative studies of ecological responses to flow alteration, and 3)study designs and other information to help inform and advance instream flow science.  SARP is managing a flow-ecology literature database.  Read More...

Demonstrations and Exercises

There are many uses for the SARP Instream Flow Resources.  In addition to developing flow-ecology relationships, they can be used to inform decisions about potential ecological impacts of a proposed water withdrawal, the status of instream flows for a state or regional water management plan, and identify priority aquatic conservation areas that are threatened by altered flow regimes.  The material in this section are intended to help users use the resources on this website efficiently and effectively.  Read More....