Latest On The Conservation Gateway

A well-managed and operational Conservation Gateway is in our future! Marketing, Conservation, and Science have partnered on a plan to rebuild the Gateway into the organization’s enterprise content management system (AEM), with a planned launch of a minimal viable product in late 2024. If you’re interested in learning more about the project, reach out to for more info!


ELOHA News Fall 2012


Practitioner Updates on the Ecological Limits of Hydrologic Alteration, a scientific framework for determining and applying environmental flows at large regional scale
October 18, 2012
1. UNESCO offers online environmental flows course
UNESCO’s new online Environmental Flows course is filling up quickly.  Set to run from December 1, 2012 to April 5, 2013, the 140-hour interdisciplinary course involves online learning, discussions, assignments, and interactions with teachers and other participants.  It was developed jointly by UNESCO-IHE, World Wildlife Fund, The Nature Conservancy, IUCN, and Deltares.
2. Flow-ecology research accelerates
A new literature review​ has found 93 studies relating flow metrics to biological responses.  The vast majority of the literature cited was generated over the last decade, with a veritable explosion corresponding with the development and publication of the ELOHA framework.  Most, however, focus on fish; there remains a need to expand the range of ecological indicators in these types of studies.

3. Mexico establishes national procedure for determining environmental flows

The NMX-AA-159-SCRI-2012 ​Norma supports the inclusion of environmental flows in all water infrastructure planning and management nationally.  The Norma opens the door for holistic methodologies, and for using adaptive approaches appropriate to the size and ecological importance of each river.  Different environmental flow standards can be set for different river systems. [download full text]

4. Landscape Conservation Cooperatives (LCCs) support ELOHA science in the USA

At least three of North America’s 22 LCCs are currently funding the science to support regional environmental flow assessment.  South Atlantic LCC leads the way with online databases of fish communities, flow-ecology literature and metadata, and GIS layers for classifying river types, and soon will have a hydrologic foundation of daily streamflow under baseline, current, and predicted future conditions; meanwhile, Desert LCC and Gulf Coast Prairie LCC are compiling flow-ecology relationships.

5. ELOHA framework tested in southeastern Queensland

The project team, led by Angela Arthington, determined that every dam in south-east Queensland alters downstream flow regimes in a different way, which rendered gradients of alteration difficult to discern.  Therefore, they found “mixed support” for ELOHA’s basic premise that rivers that share similar natural flow regimes exhibit similar ecological responses to flow regime change.  The project website explains many other results of the 4-year effort.

6. US Water Census serves up databases for ELOHA

The USGS Water Census is developing a National Data Portal to serve baseline hydrographs, hydrologic metrics, and biological observations directly to stakeholders. Three ongoing Focus Area Studies in the Apalachicola-Chattahoochee-Flint, Colorado, and Delaware River Basins are relating daily water withdrawals to changes in the abundance of fluvial specialists, estimating the extent of habitat needed to support aquatic species under different flow volumes and aquifer levels, and modeling the effects of alternative water management scenarios on habitat availability for key native species. These Water Census studies are intended to be highly transferable well beyond their immediate study areas in which they were developed.  Water Census is part of the WaterSMART program. [download press release] 

7. Baseline Streamflow Estimator (BaSE) calculates daily flow series for ungaged sites

The U.S. Geological Survey, in cooperation with the Pennsylvania Department of Environmental Protection, Susquehanna River Basin Commission, and The Nature Conservancy, created the Baseline Streamflow Estimator (BaSE) to estimate baseline (naturalized) daily streamflow data for ungaged streams in Pennsylvania.  BaSE uses a methodology that equates streamflow as a percentile from a flow duration curve for a particular day at an ungaged location with streamflow as a percentile from the flow duration curve for the same day at a reference streamgage. This tool was modeled after the Massachusetts Sustainable Yield Estimator, and a similar method will be used in New York.  Download the free BaSE tool, report, and users guide​.

8. Strategic Action Programme conserves the Okavango River system

Angola, Namibia and Botswana own one of the world’s natural treasures – the Okavango River. Flowing into the Kalahari Desert, it terminates in the Okavango Delta, one of the world’s largest Ramsar sites. The Delta is the largest wetland in southern Africa and supports one of the world’s largest concentrations of free-roaming large mammals. The Member States recently completed the Cubango-Okavango River Basin Transboundary Diagnostic Analysis to guide development planning to conserve this virtually pristine system. The analysis included an e-flows assessment using the holistic method DRIFT. The findings informed a Strategic Action Programme of interventions that have now started.  

9. Connecticut River watershed named first US National Blueway

Secretary of the Interior Ken Salazar signed a Secretarial Order on May 24, 2012 establishing the National Blueways System (NBS) and designated the 410-mile Connecticut River and its 7.2 million-acre watershed as the first National Blueway. The NBS recognizes river systems conserved through diverse stakeholder partnerships that use a comprehensive watershed approach to resource stewardship.  One Connecticut River partnership aims to integrate the operations of 70 large dams throughout the watershed to achieve ecological outcomes and other objectives.  The partnership has created daily and sub-daily flow simulation and optimization models that stakeholders and dam owners are using for Federal Energy Regulatory Commission (FERC) relicensing. The National Blueway designation is expected to facilitate the coordination of numerous Federal agencies to integrate water management across the watershed.  For more information, contact Kim Lutz.

10. Alabama state agencies initiate water policy reform 

A rare collaboration between five separate state agencies has set the stage for protecting water resources from over-allocation, for which no legal mechanism currently exists.  Their new report​ recognizes the importance of maintaining both inter- and intra-annual flow variability, and provides options and considerations for doing so. 

11. New projects

Projected climate and land-use change impacts on aquatic habitats in the US Midwest

The Midwestern regional-scale assessment will identify river reaches in the Glacial Lakes region that are most vulnerable to potential impacts of projected climate and land use changes. Because fish assemblages are strongly influenced by river water temperature and flow regimes, which are in turn affected by climate and land use, researchers will attempt to model fish habitat response to climate and land use changes through changes in temperature and flow.

Delaware River basin ELOHA 

In spring 2012, Delaware River Basin Commission contracted with The Nature Conservancy to complete an ecological flow study of the Delaware River Basin.  The project will take a similar approach to basinwide studies of the Susquehanna River​Ohio River (Pennsylvania portion) and the Great Lakes (New York portion). The USGS WaterSMART Initiative will contribute basinwide hydrologic modeling, habitat suitability modeling, and flow-ecology models.  For more info, see the attached project description or contact: Michele DePhilip.

Flow-Ecology Relationships in Desert Southwest Rivers

The Desert Landscape Conservation Collaborative (LCC) has awarded The Nature Conservancy $105,000 to define ecosystem water needs and evaluate the impacts of climate change and proposed new water diversions on the Upper Gila River in New Mexico, USA.   The 1.5-year project includes a scientific literature review and facilitated expert workshop to define relationships between flow regimes and riparian and aquatic ecology of southwestern desert rivers.  For more info, contact: Martha Schumann.

12.  New publications

Armstrong, D. S., T. A. Richards, and S. B. Levin. 2011. Factors influencing riverine fish assemblages in Massachusetts. U.S. Geological Survey Scientific-Investigations Report 2011-5193, 58p. [full text]

Arthington, Angela H. 2012 Environmental Flows: Saving Rivers in the Third Millennium University of California Press, 424 p.  ELOHA is well covered in a new book just published by.  This book describes river values, principles of river ecology, the impacts of altered flow regimes, and methodological developments from the simplest hydrological formulas to large-scale environmental flow frameworks (e.g. DRIFT and ELOHA) that inform water management. [abstract]

Benson, R. D. 2011. Public funding programs for environmental water acquisitions: origins, purposes, and revenue sources. Environmental Law 42(1). [abstract]

Burkhead, N. M. 2012. Extinction rates in North America freshwater fishes, 1900-2010. Bioscience 62: 798-808. From 1900-2010, freshwater fish species in North America went extinct at a rate 877 times faster than the rate found in the fossil record.  Since 1989, the numbers of extinct North American fishes have increased by 25%. [abstract]

Cooper, D.J. and Merritt, D.M. 2012. Assessing the water needs of riparian and wetland vegetation in the western United States. Gen. Tech. Rep. RMRSGTR-282. This USDA-Forest Service report is intended to assist water managers in determining environmental flow needs.  It discusses wetland and riparian classification, characteristics and ecology; surface and groundwater hydrology; plant physiology and population and community ecology; and techniques for linking attributes of vegetation to patterns of surface and groundwater and soil moisture.  Several case studies are also presented. [full text]

Garrick, D., McCoy, A., and Aylward, B. 2011. The Cornerstones Report: market-based responses to Arizona's water sustainability challenges. Ecosystem Economics. [full text]

Hitt, N. P., S. Eyler, and J. E. B. Wofford. 2012. Dam removal increases American eel abundance in distant headwater streams. Transactions of the American Fisheries Society 131: 1171-1179. [abstract] [press release]

Eng, K., Carlisle, D. M., Wolock, D. M. and Falcone, J. A. (2012),Predicting the likelihood of altered streamflows at ungaged rivers across the conterminous United States. River Res. Applic. doi: 10.1002/rra.2565. “The results of these analyses suggest that the primary predictors of altered streamflow regimes across the Nation are (i) the residence time of annual runoff held in storage in reservoirs, (ii) the degree of urbanization measured by road density and (iii) the extent of agricultural land cover in the river basin.” [abstract]

Finn, M., and S. Jackson. 2011. Protecting indigenous values in water management: a challenge to conventional environmental flow assessments. Ecosystems 14: 1232-1248. DOI: 10.1007/s10021-011-9476-0.  Figure 3 inserts indigenous values into Poff et al’s ELOHA flow chart. [abstract]

Freeman, M. C., G. R. Buell, L. E. Hay, W. B. Hughes, R. B. Jacobson, J. W. Jones, S. A. Jones, J. H. Lafontaine, K. R. Odom, J. T. Peterson, J. W. Riley, J. S. Schindler, C. Shea, and J. D. Weaver. 2012. Linking river management to species conservation using dynamic  landscape-scale models. River Research and Applications DOI:10.1002/rra.2275 [abstract]

Kendy, E., C. Apse, and K. Blann. 2012. A practical guide to environmental flows for policy and planning, with nine case studies from the United States. The Nature Conservancy.  Learn how six states and three interstate river basins effectively developed and applied regionalized environmental flow criteria to water resource planning, water withdrawal permitting, and multi-dam re-operation.  These case studies and recommendations bridge the ELOHA framework from theory to practice, demonstrating its application in a wide range of biophysical and socio-political contexts. [full text]

King, J. and Pienaar, H. (Eds) 2011. Sustainable use of South Africa’s inland waters: A situation assessment of Resource Directed Measures 12 years after the 1998 National Water Act. Water Research Commission Report No. TT 491/11. Water Research Commission, Pretoria.  259 pp. South Africa reviews its progress with the protection of aquatic ecosystems. Written by 12 lead authors and 30 contributing authors, a new book analyses the strengths and weaknesses of South Africa’s application of its world-acclaimed NWA. After an initial two background chapters there are six on implementation, which describe how the country has mobilised to balance the demands for water with the need to protect its rivers, wetlands, estuaries and groundwater. Hard copies available for $70 + shipping:

Konrad, C. P., Olden, J. D., Lytle, D. A., Melis, T., Schmidt, J. C., Bray, E. N., Freeman, M. C., Gido, K. B., Hemphill, N. P., Kennard, M. J., McMullen, L. E., Mims, M. C., Pyron, M., Robinson, C. T., and Williams, J. G. 2011. Large-scale flow experiments for managing river systems.  Bioscience 61(12):948-959. [abstract]

Leigh, C., B. Stewart-Koster, F. Sheldon, and M. A. Burford. 2012. Understanding multiple ecological responses to anthropogenic disturbance: rivers and potential flow regime change. Ecological Applications 22: 250-263. DOI: 10.1890/11-0963.1. [abstract]

McManamay, R. A., Orth, D. J., Dolloff, C. A., and Frimpong, E. A. 2011. A regional classification of unregulated stream flows: spatial resolution and hierarchical frameworks.  River Research and Applications DOI: 10.1002/rra.1493. [abstract]

McManamay, R. A., Orth, D. J., Dolloff, C. A., and Frimpong, E. A. 2011. Regional frameworks applied to hydrology: can landscape-based frameworks capture the hydrologic variability?  River Research and Applications DOI:10.1002/rra.1535. [abstract] 

Merritt, D. M., and H. L. Bateman. 2012. Linking stream flow and groundwater to avian habitat in a desert riparian system. Ecological Applications. DOI: 10.1890/12-0303.1. [abstract]

Mims, Meryl C., and Julian D. Olden. 2012. Life history theory predicts fish assemblage response to hydrologic regimes. Ecology 93:35–45. DOI: 10.1890/11-0370.1. [abstract]

Murphy, J. C., Knight, R. R., Wolfe, W. J. and S. Gain, W. 2012. Predicting ecological flow regime at ungaged sites: a comparison of methods.  River Res. Applic. DOI: 10.1002/rra.2570 “Results suggest that a rainfall–runoff model calibrated on a single characteristic is less likely to perform well as a predictor of a range of other characteristics (flow regime) when compared with a regional regression model calibrated individually on multiple characteristics used to represent the flow regime. Poor model performance may misrepresent hydrologic conditions, potentially distorting the perceived risk of ecological degradation. Without prior selection of streamflow characteristics, targeted calibration, and error quantification, the widespread application of general hydrologic models to ecological flow studies is problematic.” [abstract]

Opperman, J. J., J. Royte, J. Banks, L. R. Day, and C. Apse. 2011. The Penobscot River, Maine, USA: a basin-scale approach to balancing power generation and ecosystem restoration. Ecology and Society 16: 7. DOI: 10.5751/ES-04117-160307. [full text]

Peake, P., J. Fitzsimons, D. Frood, M. Mel, N. Withers, M. White, and R. Webster. 2011. A new approach to determining environmental flow requirements: Sustaining the natural values of floodplains of the southern Murray-Darling Basin. Ecological Management and Restoration 12: 128-137. DOI: 10.1111/j.1442-8903.2011.00581.x. [abstract]

Siebentritt, M.A. (ed.) 2012. Water trusts:  What role can they play in the future of environmental water management in Australia?  Proceedings of a December 2011 workshop.  Australian River Restoration Centre and Water Trust Alliance. 34 p. [download full text]

Turner, D. S., and H. E. Richter. 2011. Wet/dry mapping: using citizen scientists to monitor the extent of perennial surface flow in dryland regions. Environmental Management 47: 497-505. DOI: 10.1007/s00267-010-9607-y. [abstract]

U.S. Department of the Interior. 2012. WaterSMART: a three-year progress report. (Ecological water use, page 51) [full text]

Wildman, R. A., and N. A. Forde. 2012. Management of water shortage in the Colorado River basin: evaluating current policy and the viability of interstate water trading. Journal of the American Water Resources Association (JAWRA) 1-12.  DOI: 10.1111/j.1752-1688.2012.00665.x. Compares enabling conditions for water trading in the Colorado River basin with those of the Murray-Darling River basin. [full text] High Country News blogged about this paper.

Zorn, T. G., P. W. Seelbach, and E. S. Rutherford. 2012. A regional-scale habitat suitability model to assess the effects of flow reduction on fish assemblages in Michigan streams. Journal of the American Water Resources Association (JAWRA) DOI: 10.1111/j.1752-1688.2012.00656.x. [abstract]​

ELOHA Toolbox website

Share your resources with the entire ELOHA community by posting them.  Case studies, references, links, and text additions all are welcome.  We especially encourage postings on environmental flow policy advances from outside the United States.  Send your contributions to Eloise Kendy​.  The site is usefully organized according to the main steps of ELOHA, with cited references linked to a comprehensive bibliography.  Case studies from around the world are being tracked, with your help.   Thank you to all contributors, past and future.


Enough studies already; where’s the action?


As you can see, many terrific initiatives are establishing the enabling conditions – especially the scientific foundation – for managing environmental flows at a regional scale.  Let’s fill the next ELOHA News with a lot more stories on actual implementation of environmental flows in water withdrawal permitting, multi-dam re-operation, and integrated river basin planning and management.  I rely on you to send me those stories.