Implementation Of Environmental Flows Research Articles

Mimicking functional elements of the natural flow regime promotes native fish recovery in a regulated river.

Streamflow regimes that maintain vital functions and processes of aquatic ecosystems are critical to sustaining ecosystem health. In rivers with altered flow regimes, restoring components of the natural flow regime is predicted to conserve freshwater biodiversity by supporting ecological functions and geomorphological processes to which native communities are adapted. However, the effectiveness of environmental flow restoration is poorly understood because of inadequate monitoring and uncertainty in ecological responses to managed changes in specific, quantifiable aspects of the annual streamflow regime. Here, we used time series models to analyze 25 years of fish assemblage data collected before and after environmental flow implementation in a dammed river in California, USA. We examined the response of the fish community to changes in individual components of the flow regime known to support ecosystem functions. We found that as functional flow components shifted toward their predicted natural range, the quasi-extinction risk (likelihood of population declines of >80%) decreased for the native fish assemblage. Following environmental flow implementation, observed changes toward natural ranges of dry season duration, fall pulse flow magnitude, and wet season timing each reduced quasi-extinction risk by at least 40% for the native assemblage. However, functional flow components that shifted away from their predicted natural range, including lower spring recession flows and higher dry season baseflow, resulted in greater quasi-extinction risk for native species. In contrast, non-native species decreased in abundance when flow components shifted toward predicted natural ranges and increased when components shifted away from their natural range. Although most functional flow components remained outside of their natural range following environmental flow implementation, our results indicate that even moderate shifts toward a natural flow regime can benefit native and suppress non-native fish species. Overall, this study provides the most compelling evidence to date of the effectiveness of functional environmental flows in supporting native fish recovery in a highly regulated river.

Assessing small hydropower viability in water-scarce regions: environmental flow and climate change impacts using a SWAT+ based tool

Water-scarce regions, like the Mediterranean, face worsening conditions due to climate change, intensifying pressure on key economic sectors such as hydropower. Additionally, environmental conservation policies, particularly the implementation of environmental flows, present challenges for hydropower systems. Certainty regarding the impact of these factors on future hydropower production is crucial for informed decision-making in the transition to sustainable energy. This study introduces S + HydPower, a tool coupled with SWAT+ to assess climate change and watershed management effects on small hydropower plant (SHP) systems. In this study, we used this tool to investigate the consequences of implementing environmental flows and climate change on run-of-river SHPs in the Catalan River Basin District (CRBD), in Catalonia. The results show that applying environmental flows would lead to a significant 27% reduction in SHP production. However, this reduction would represent only 0.25% of the region’s current energy demand. Furthermore, the study reveals a potential 38% to 73% reduction in SHP production by the end of the twenty-first century due to the combined effects of environmental flows and climate change. This suggests a substantial decline in run-of-river SHP’s contribution to the CRBD’s electricity supply. These findings emphasize the need to explore alternative and sustainable energy sources to ensure the long-term reliability and resilience of the region’s energy supply.

Water Reserves for the Environment: A Strategic and Temporal Analysis (2012–2022) for the Implementation of Environmental Flows in Mexico

In Mexico, the evaluations of environmental flows are regulated by the Mexican Norm NMX-AA-159-SCFI-2012, and they warrant the establishment of water reserves for the environment. However, the pressure or demand for water use limits the establishment of said reserves because their implementation is generally conditioned to water availability. This research aimed to evaluate the changes through time of the variables that serve as a basis for the implementation strategy by the Mexican government. A geographical information system was built with updated information on water availability, conservation values, and pressures for all basins nationwide. Their desired conservation status was analyzed, and the potential reserves were estimated based on the reference values. The results were examined according to the ranking changes in environmental water reserves enactment feasibility and desired conservation status of Mexican basins, the progress achieved to date, and the potential contribution to the conservation of protected areas and their connectivity if the gaps of reserves were implemented. The outcomes point towards an administrative implementation strategy with positive results despite the growing demand for water use, with a change rate higher than the one for the creation of new protected areas. Currently, basins with low demand and high conservation value have the potential to meet people’s and the environment’s water needs, and contribute to 86% of the goal set by the present administration without affecting water availability. Finally, reserving water in the priority basins would guarantee the legal protection of the flow regime in 48–50% of the hydrographic network (63,760–66,900 km) in a desired conservation status, 43–49% of wetlands of international importance (48,650–49,600 km2) and other protected areas (128,700–136,500 km2) in 85–89% of the global ecoregions represented in Mexico (780,500–852,200 km2).

Accelerating environmental flow implementation to bend the curve of global freshwater biodiversity loss

Environmental flows (e-flows) aim to mitigate the threat of altered hydrological regimes in river systems and connected waterbodies and are an important component of integrated strategies to address multiple threats to freshwater biodiversity. Expanding and accelerating implementation of e-flows can support river conservation and help to restore the biodiversity and resilience of hydrologically altered and water-stressed rivers and connected freshwater ecosystems. While there have been significant developments in e-flow science, assessment, and societal acceptance, implementation of e-flows within water resource management has been slower than required and geographically uneven. This review explores critical factors that enable successful e-flow implementation and biodiversity outcomes in particular, drawing on 13 case studies and the literature. It presents e-flow implementation as an adaptive management cycle enabled by 10 factors: legislation and governance, financial and human resourcing, stakeholder engagement and co-production of knowledge, collaborative monitoring of ecological and social-economic outcomes, capacity training and research, exploration of trade-offs among water users, removing or retrofitting water infrastructure to facilitate e-flows and connectivity, and adaptation to climate change. Recognising that there may be barriers and limitations to the full and effective enablement of each factor, the authors have identified corresponding options and generalizable recommendations for actions to overcome prominent constraints, drawing on the case studies and wider literature. The urgency of addressing flow-related freshwater biodiversity loss demands collaborative networks to train and empower a new generation of e-flow practitioners equipped with the latest tools and insights to lead adaptive environmental water management globally. Mainstreaming e-flows within conservation planning, integrated water resource management, river restoration strategies, and adaptations to climate change is imperative. The policy drivers and associated funding commitments of the Kunming–Montreal Global Biodiversity Framework offer crucial opportunities to achieve the human benefits contributed by e-flows as nature-based solutions, such as flood risk management, floodplain fisheries restoration, and increased river resilience to climate change.

Measures to safeguard and restore river connectivity

Freshwater connectivity and the associated flow regime are critical components of the health of freshwater ecosystems. When freshwater ecosystems are fragmented, the movements and flows of species, nutrients, sediments, and water are altered, changing the natural dynamics of freshwater ecosystems. The consequences of these changes include declines and loss of freshwater species populations and freshwater ecosystems, and alterations in the delivery of certain ecosystem services, such as fisheries, buffering of flood events, healthy deltas, recreational and cultural values, and others. Measures exist that can maintain and restore connectivity or mitigate against its loss in the face of constructed barriers or other habitat alterations. These measures include system-scale planning for energy and water resources that includes options for limiting loss of freshwater connectivity; putting in place protections for keeping critically important freshwater habitats connected; mitigating impacts on freshwater ecosystems via barrier design, fish passage, or implementation of environmental flows; and restoring freshwaters via barrier removal and reconnection of rivers, wetlands, and floodplains and via active management of groundwater recharge. We present case studies of measures applied in Europe, Asia, Africa, and the Americas and reflect on the next generation of innovation needed to further enhance and advance the implementation of restoration and protection and the mitigation of freshwater connectivity impacts.

Future-proofing the emergency recovery plan for freshwater biodiversity

Freshwater biodiversity loss is accelerating globally, but humanity can change this trajectory through actions that enable recovery. To be successful, these actions require coordination and planning at a global scale. The Emergency Recovery Plan for global freshwater biodiversity aims to reduce the risk for freshwater biodiversity loss through six priority actions: (1) accelerate implementation of environmental flows; (2) improve water quality to sustain aquatic life; (3) protect and restore critical habitats; (4) manage exploitation of freshwater species and riverine aggregates; (5) prevent and control nonnative species invasions in freshwater habitats; and (6) safeguard and restore freshwater connectivity. These actions can be implemented using future-proofing approaches that anticipate future risks (e.g., emerging pollutants, new invaders, and synergistic effects) and minimize likely stressors to make conservation of freshwater biodiversity more resilient to climate change and other global environmental challenges. While uncertainty with respect to past observations is not a new concern for freshwater biodiversity, future-proofing has the distinction of accounting for the uncertainty of future conditions that have no historical baseline. The level of uncertainty with respect to future conditions is unprecedented. Future-proofing of the Emergency Recovery Plan for freshwater biodiversity will require anticipating future changes and developing and implementing actions to address those future changes. Here, we showcase future-proofing approaches likely to be successful using local case studies and examples. Ensuring that response options within the Emergency Recovery Plan are future-proofed will provide decision makers with science-informed choices, even in the face of uncertain and potentially new future conditions. We are at an inflection point for global freshwater biodiversity loss; learning from defeats and successes can support improved actions toward a sustainable future.

A legislative framework for environmental flow implementation: 30‐years operation in Japan

AbstractThe Japanese environmental flow (e‐flow) concept and framework are outlined in the current study. We first review the natural and historical background related to the establishment and implementation of the e‐flow framework in Japan. We then summarize the national guidelines used to assess e‐flows. Finally, we discuss a river for which the guidelines have been applied to set e‐flow requirements. It is legally mandated that flows be established to maintain the riverine environments of class A rivers managed by the national government. These correspond to e‐flows, which are referred to as maintenance flows in Japan. A Guideline established in 1997 provides detailed instructions on how to assess e‐flows, and the e‐flow framework has been implemented for 100 class A rivers according to the guidelines. E‐flow objectives in Japan are intended to benefit ecosystems through the protection of river habitats and fisheries and the protection and maintenance of water quality, groundwater levels, riverine scenery, and navigable waterways. E‐flow objectives also address cultural and social needs, such as the prevention of salt damage and estuary clogging, and the protection of wooden infrastructure management facilities. Although Japanese rivers are characterized by large fluctuations and sudden peaks in flow, there has been little discussion about e‐flow evaluation methods that take flow variability into consideration. This is because dams on Japanese river basins control only a small percentage of total runoff volume. This is one reason why the guidelines for setting e‐flows focus only on the minimum flows required to prevent extreme low‐flow conditions.

Hydrologic classification of Tanzanian rivers to support national water resource policy

AbstractClassifying rivers into homogeneous categories based on hydrological and/or environmental attributes supports the implementation of environmental flows to sustain aquatic ecosystems and support the resource needs of society. Hydrological classifications provide decision‐makers with a pragmatic number of water management units by grouping individual rivers or river segments expected to exhibit similar biophysical responses to flow alteration. Such classifications are particularly useful across broad geographies and in data‐limited contexts, such as in Tanzania, where the legal requirement to implement environmental flows for all major waterbodies remains constrained by scant data. We present a two‐level hydrological classification of all Tanzanian basins and the Rufiji River Basin. For the Rufiji River Basin, the largest river basin in the country, we performed an inductive classification based on the availability of long‐term time series of daily average discharge. We clustered 28 gauging stations into seven classes according to ecologically relevant hydrological metrics and used boosted classification trees to predict the hydrological class of all 95,909 river segments in the basin based on environmental attributes that influence flow regimes. In the absence of consistent, readily‐available gauged flow data, we conducted a deductive classification of all Tanzanian rivers whereby segments were directly grouped by multivariate similarity using the same environmental attributes. This analysis revealed 10 river classes reflecting the diversity of ecohydrological conditions characterizing the 486,681 river segments draining in and out of Tanzania. The new hydrological classifications presented here provide the foundation to guide implementation of management practices within the water policy framework of Tanzania.

Climate‐linked freshwater habitat change will have cost implications: Pest blackfly outbreaks in two linked South African rivers

AbstractCalls for implementation of environmental flows have been growing over the past 20 years, and their implementation is now being recognized. The need for such assessments to occur in conjunction with maintenance of environmental water temperatures has also been emphasized. When the costs of departures from natural thermal regimes are considered, this moves from being an academic exercise to a tangible management imperative. Pest outbreaks of aquatic macroinvertebrates typically occur when environmental conditions disproportionately and overwhelmingly favor a particular species. This has been the case for at least three major river systems of economic importance in South Africa, namely, the Orange River and its major tributary (Vaal River) as well as the Great Fish River. In these rivers, two species of pest blackfly, Simulium chutteri and S. damnosum (Diptera: Simuliidae), have become problematic following on from changes in natural flows through either impoundment or interbasin transfers. In this study, a statistically robust reference thermal condition was defined and exceedances assessed (based on a 2°C increase in water temperatures). The implications of these assessments were then applied to future possible pest blackfly outbreaks, factoring in changes in flows in response to global climate change. Results show that the current seasonal variation in the likelihood of pest outbreaks is replaced by high perpetual outbreak probabilities. Interactions between major environmental variables become synergistic, with major cost implications to regional economies. Lessons from this study can be generalized and used as a means of predicting similar synergistic effects in other aquatic macroinvertebrate disease vectors (such as bilharzia vector snails and mosquitoes) in response to global climate change.

Assessment and Implementation of Environmental Flows to Restore River Gomti- a Tributary of Ganga, India

Environmental flows in rivers are essential to maintain their natural regime, purify themselves, sustain aquatic life and vegetation, recharge groundwater and support livelihoods. Rivers play their role in people’s cultural and spiritual lives. These functions are possible with a suitable e-flow regime. This paper aims to quantify E-Flows for alluvial river Gomti- a tributary of river Ganga, at upstream and downstream of Lucknow City, at Sultanpur and at Jaunpur. These E-flow sites were chosen on the basis of homozonation study of Gomti Basin. Two methodsHydrological consideration and holistic approach: Building Block Methodology has been employed for assessing the Eflows at four sites falling in middle and lower zone of the Gomti Basin. The two set of E-Flows obtained have been compared with observed flows and virgin flows limits to visualize the implications of implementation plan for normal maintenance year and drought year. Considering Gomti basin water plan for 2045 while trying to meet future sectoral water demand and managing e-flows minimum allocation, the paper argues for e-flows implementation by participatory wetland conservation and improvise agricultural water use efficiency. Summary of investment plan in Gomti Basin to manage demand and supply of water optimally including minimum e-flows in Gomti river. Freed water from agriculture may be diverted into river Gomti from irrigation canal systems, offtaking from Sharda and Ghaghara rivers passing through the Gomti basin. It is found that recommended monthly E-flows for Mehndighat is higher than the observed flows and even more than virgin flow volume except in the month of July. At Fuslauna site E-flows are higher than estimated virgin and observed flow for the months of January to June and for rest of the months July to December, E-flows values are within virgin/observed flow volume limits. Hence to implement Eflows in Gomti river at Fusluana site, additional water from Sharda Sahayak Feeder, through Gomti escape has to be released for lean flow months January to June. Augmentation of flows in Gomti river is recommended by increasing base flows contribution particularly during lean flow months. For Sultanpur and Jaunpur sites required e-flows are almost twice higher than the present day flows in Gomti river. E-flows for Gomti river at Jaunpur is higher than the virgin flow for the month of January to June, estimated at Maighat - a d/s CWC site below Jaunpur. Alternatively, based on MOWR guidelines (as issued in case of Ganga river) considering only hydraulic perspective, minimum E-Flows for Gomti river at Lucknow, Sultanpur, Jaunpur and Maighat has been calculated. E-Flow estimates for Lucknow comes to 15.02 m3 /s, 7.70 m3 /s and 3.41m3 /s during monsoon (June to Sep.), non lean flow month (Oct & Nov.) and lean flow months Dec to May respectively. For Sultanpur site 42.70 m3 /s, 23.73 m3 /s and 10.26m3 /s and for Jaunpur site 44.94 m3 /s, 29.22 m3 /s and 11.28m3 /s has been obtained for the same period. E-flows assessed applying BBM, monthly discharge ranges are for Mehndighat 40-415 m3 /s, Aqueduct site 40-58 m3 /s, Sultanpur 92-950 m3 /s and for Jaunpur site 100-795 m3 /s. During wet months flushing requirement for two weeks period is 310 m3 /s at Lucknow, 1370 m3 /s at Sultanpur and 2450 m3 /s for Jaunpur. This peak flow appears possible at Lucknow due to barrage but difficult to implement at Sultanpur and Jaunpur . Although ever maximum discharge observed had been at Lucknow 916.97m3 /s, at Sultanpur 1373.68 m3 /s at Jaunpur 2991.82 m3 /s and at Maighat 3521.53 m 3 /s but on average and 75% dependability level these flow becomes very low. It is suggested that E-Flows assessed for Gomti river using BBM may be refined on the basis of more research carried out with informed hydrology, biodiversity habitat conditions and parameters of geomorphology.

Classification of aquatic macroinvertebrates in flow categories for the adjustment of the LIFE Index to Costa Rican rivers

The LIFE Index can be useful to determine the effect of changes in river flow on the community of aquatic macroinvertebrates and as a tool for the implementation of environmental flows. This study demonstrates how to classify aquatic macroinvertebrates into a flow category in order to adjust the LIFE Index to Costa Rica. A panel of experts was surveyed to classify the most common genera into a water velocity category, based on their experience. Also, for one-year, aquatic macroinvertebrates were collected in the low and middle basin of the Naranjo River under different velocities, and by using the TITAN2 package, their respective thresholds for current velocity were determined. Variation was observed in the responses of the expert panel; however, several taxa overlapped by more than 60% between the expert classification and the TITAN2 test results. The TITAN2 test assigned a velocity threshold to 32 genera, with the inflection point being 0.1 m/s. The expert panel served as a tool to assign a category to those genera that the TITAN2 test did not contemplate. Organisms without morphological adaptations to survive fast flowing conditions decreased in frequency above 0.1 m/s, while genera related to moderate and high velocities increased in frequency. Through the panel of experts and the TITAN2 test, it was possible to assign the most common genera in the country to a current velocity category and therefore adjust the LIFE index.

Editorial: Implementing Environmental Flows: Lessons for Policy and Practice

Water resources and freshwater ecosystems are under pressure from a growing human population, thirstier lifestyles, and climate change (UNESCO and UN water, 2020). Consequently, water-related risks to society are increasing (World Economic Forum, 2020) and freshwater biodiversity is rapidly declining (Grooten, 2018). The UN Sustainable Development Goals (SDGs) include targets for improved water management, including SDG 6.4, which stipulates sustainable water withdrawals, and SDG 6.6, aimed at halting the degradation of water-related ecosystems. The hydrological regimes of rivers and other wetlands can be regarded as a litmus test of whether these targets are met (Tickner and Acreman, 2013). Environmental flow assessment (EFA) is the science-based process of determining appropriate flow regimes for individual water bodies given environmental, socio-economic and cultural objectives. Researchers have developed sophisticated EFA tools (Acreman et al., 2014; Poff et al., 2017) but implementation of environmental flows has been problematic, and research into the challenges of implementation is scarce.

Comparing Environmental Flow Implementation Options with Structured Decision Making: Case Study from the Willamette River, Oregon

AbstractMany frameworks have been used to identify environmental flows for sustaining river ecosystems or specific taxa in the face of widespread flow alteration. However, these frameworks largely focus on identifying suitable flows and often ignore the important links between management actions, resulting flows, and valued ecosystem or social responses. Structured decision making (SDM) could assist the comparison of environmental flows by providing a mature framework to link management actions to objectives via environmental flow science. We describe SDM and illustrate its application using a case study focused on comparing environmental flow scenarios for the mainstem Willamette River, Oregon. In a short timeframe, SDM was applied to identify objectives, develop empirical and expert opinion‐based models, and compare flow scenarios while accounting for interannual flow variability and partial controllability. No scenario was clearly preferred based on available knowledge, largely because river flows could only be partially controlled through dam operations. Participants agreed that SDM was useful for comparing alternative dam operations, but that refined predictive models and additional objectives were needed to better inform basinwide flow decisions. In our view, SDM can provide more realistic comparisons of environmental flows by accounting for partial controllability and uncertainty, which may result in greater implementation of available flow management actions.

Bending the Curve of Global Freshwater Biodiversity Loss: An Emergency Recovery Plan.

Despite their limited spatial extent, freshwater ecosystems host remarkable biodiversity, including one-third of all vertebrate species. This biodiversity is declining dramatically: Globally, wetlands are vanishing three times faster than forests, and freshwater vertebrate populations have fallen more than twice as steeply as terrestrial or marine populations. Threats to freshwater biodiversity are well documented but coordinated action to reverse the decline is lacking. We present an Emergency Recovery Plan to bend the curve of freshwater biodiversity loss. Priority actions include accelerating implementation of environmental flows; improving water quality; protecting and restoring critical habitats; managing the exploitation of freshwater ecosystem resources, especially species and riverine aggregates; preventing and controlling nonnative species invasions; and safeguarding and restoring river connectivity. We recommend adjustments to targets and indicators for the Convention on Biological Diversity and the Sustainable Development Goals and roles for national and international state and nonstate actors.

Classifying Dams for Environmental Flow Implementation in China

The implementation of environmental flows is of the utmost importance for ecosystem protection and restoration in dammed rivers. A key challenge in optimizing dam regulation is the uncertainty of the ecohydrology relationship between flow release and ecological response. In the present paper, we develop a framework of dam classification to organize the categories of the ecohydrology relationship for implementing environmental flows. Dams are classified from three major categories that differ in dam properties, hydrological alteration, and downstream hydrobiological diversities based on the relationship of hydrology and ecology. Finally, 773 dams in China are screened and ranked into four classes involving a great diversity of environmental flow components. A classification of dams that utilizes the implementation of environmental flows is presented. (1) Class 1 includes dams with rare and endangered fish species in the downstream. It is the category with the highest priority for environmental flow releases and regulation, requiring continuous flow and flood pulse components for fish spawning and migration. (2) Class 2 includes dams with significant hydrological alteration in the downstream. It is the category with second priority for environmental flow releases and regulation, requiring natural hydrological regimes simulation or complete flow component recovery for optimizing the flow duration curve and mitigating adverse impacts of dam operation. (3) Class 3 includes dams with a high degree of regulation where there is urgency for environmental flow releases and regulation, requiring that minimum flow is guaranteed by cascade reservoir regulation. (4) Class 4 includes dams with a low degree of regulation where there is less urgency for environmental flow releases and regulation. This classification method is important for future research, including environmental flow release regulation and the effectiveness evaluation of environmental flow adaptive management. It will be useful for guiding the implementation of environmental flows.

Assessing the Establishment and Implementation of Environmental Flows in Spain

The alteration of natural flows due to water withdrawals and the presence of hydraulic infrastructure poses significant threats to the integrity of riverine ecosystems. The establishment of environmental flows (EF) has been conceived as a water management tool to mitigate the impact of in-stream flows alteration. To date, a large body of literature has focused on methods to define EF, but less attention has been paid to documenting and assessing their actual implementation on the ground. This article provides a framework to describe and assess the process of design, application, and monitoring of EF at a river basin level. The framework is applied to Spain, where significant efforts have been made during the past decade to define and implement EF across the country. The goal of the paper is to identify strengths and opportunities for improving the implementation of EF at country level. The Spanish legislation establishes that EF should contribute to the achievement of the good ecological status of surface water bodies as required by the European Union Water Framework Directive. Several pitfalls in the design, application, and monitoring of this important river management measure constrain the ability of the existing EF to deliver that fundamental outcome.

Challenges to Implementing an Environmental Flow Regime in the Luvuvhu River Catchment, South Africa.

Rivers are now facing increasing pressure and demand to provide water directly for drinking, farming and supporting industries as a result of rapidly growing global human population. Globally, the most common practice for catchment managers is to limit water abstraction and changes to stream flow by setting environmental flow standards that guard and maintain the natural ecosystem characteristics. Since the development of the environmental flow concept and methods in South Africa, very few studies have assessed the institutional constraints towards environmental flow implementation. This study determined stream flow trends over time by fitting simple linear regression model to mean daily stream flow data at three selected stations in the Luvuvhu River Catchment (LRC). We also conducted a literature search to review, firstly the response of aquatic organisms (fish and macroinvertebrate) to changes in habitat conditions and secondly on local challenges affecting the sustainable implementation of environmental flow regime and related water resources management strategies. All the three stream flow stations show decreasing stream flow volume of 1 and 2 orders of magnitude faster in some stations with the possibility that flow will cease in the near future. Qualitative analyses from both local and international literature search found that the main challenges facing the implementation of sustainable flow strategies and management are absence of catchment management agency, lack of understanding of environmental flow benefits, limited financial budget, lack of capacity and conflict of interest. Rivers with changing stream flows tend to lose sensitive species. The development of scientifically credible catchment-wide environmental flow and abstraction thresholds for rivers within the LRC would make a major contribution in minimizing the declining stream flow volumes. Monitoring and reporting should be prioritized to give regular accounts of the state of our rivers.

Securing Environmental Flows Through System Reoperation and Management: Lessons From Case Studies of Implementation

Water-management infrastructure, such as dams, diversions, and levees, provides important benefits to society, including energy, flood management and water supply, but this infrastructure is a primary cause of the decline of freshwater ecosystems and the services they provide. Due to these declines, recent attention has focused on improving the environmental performance of water infrastructure, such as modifying the location, design or operation of infrastructure to maintain or restore environmental flows. Despite growing attention to the importance of environmental flows, and continued advancement in flow assessment methods, implementation of flow protection or restoration has lagged expectations. In this paper we describe how pursuing environmental flows at the scale of infrastructure systems, rather than individual sites, such as a dam, offers two pathways to increased implementation of environmental flows. First, policy and management mechanisms that apply to large areas—river basins or political jurisdictions—can catalyze large-scale implementation of flow protection or restoration. We provide two examples of system-scale policy and management mechanisms: flow protection policies and system-scale hydropower planning and management. Although system-scale policy and management offer a clear path to large-scale implementation, there will continue to be a need for flow implementation that occurs at smaller scales, such as a high priority river reach. The second pathway focuses on implementation at that scale—such as environmental flow releases from a dam or small set of dams—but embeds dam reoperation or site-scale flow implementation within reoperation of the larger systems of resource management within which the dam or ecosystem is located. These systems of resource management can encompass various sectors and here we provide examples of dam reoperation or flow implementation facilitated by solutions that included changes to the management of (1) water supply systems; (2) floodplains; and (3) irrigation systems. We illustrate both of these system-scale pathways through a set of case studies, drawn primarily from North America, each of which includes an example of current implementation.

Towards a Healthy Ganga—Improving River Flows Through Understanding Trade Offs

WWF-India along with its partners is working towards the conservation of Ganga since last decade. During 2015-16, along with partners, WWF-India conducted an action research study in over 2 million hectare of culturable command area of two irrigation systems taking off from River Ganga, to understand the barriers to implementation of Environmental Flows (E-Flows) in the Ganga. Under this initiative, the team tried to bridge the knowledge gap about potential trade-offs for implementation of E-Flows in a critical stretch of Ganga. The team made an attempt to understand the surface water allocation and water use scenario in western and central part of the state of Uttar Pradesh, where the Ganga water is used for agriculture purpose through major irrigation infrastructure. The E-Flows recommendations for critical locations downstream of two barrages, i.e. head-works of two major irrigation schemes, were developed. A framework was developed to assess the costs and benefits of various flow regimes. Such a framework helps discuss the trade-offs emerging from E-Flows releases onto other committed allocations across various users. This paper discusses approaches for management of trade-offs to restore E-Flows in this stretch of Ganga, and include various management options – like (i) promotion of irrigation water use efficiency, (ii) gradual and marginal shift in land towards less-water intensive crops and (iii) institutional aspects. The paper argues that, whilst there is a widespread apprehension that, any curtailment in the allocation quota for irrigation would lead to adverse impact onto the farming community; but actually after assessing the trade-offs, it can be inferred that, the E-Flows implementation in this stretch of Ganga would require enhancement of water in the river, but that requirement is not substantial. Towards the end of the paper, challenges and opportunities for E-Flows implementation in the Upper Ganga are discussed. This paper attempts to discuss one of the newer approach in which, economic analysis has been used to articulate the rational for implementation of E-Flows regime.

Environmental Flows Under the WFD Implementation

The Water Framework Directive (WFD) is the first piece of European environmental legislation addressing hydromorphological modifications and impacts on water bodies. Accordingly, in those water bodies where the hydromorphological pressures are having an impact on the ecological status, action is needed to achieve WFD objectives. Environmental flows appeared as one of the answers to this challenge. Due to their importance, Member States (MSs) have been looking to integrate ecological flows in the River Basin Management Plans (RBMPs) and Programmes of Measures (PoMs). More than seventeen years after the WFD adoption, this study aims to provide a systematic review of the use of environmental flows within the process of WFD implementation and their contribution to the achievement of environmental objectives. In order to achieve the goals of the study, a special analysis was done using: i) the WFD official documentation reporting the progress of WFD and environmental flows definition and implementation (such as the CIS Guidance n° 31), as well as, ii) the answers to key questions addressed to EU MSs representatives involved in the implementation of environmental flows. These enabled us to perceive how this topic has been addressed in MSs. Based on the gathered information the authors assessed whether a change in the environmental flows’ situation, between the 1st and 2nd RBMPs, has occurred by each MS, or whether progress on environmental flows assessments has been made. Furthermore, this study also highlights some MSs representatives comments related with the role of the Guidance n°31 and some relevant information related with the 3rd RBMPs. Even though an evolution on environmental flows assessments can be perceived, with an increase in MSs defining and incorporating environmental flows within the 2nd RBMPs and in the complexity of the conducted approaches, there is still a long way to go. Namely, it could be highlighted that more efforts are required for the: i) implementation of environmental flows and the monitoring of its effects in the water bodies status, ii) development of a verifiable link between environmental flows and biological indicators.