Provision of environmental flows promotes spawning of a nationally threatened diadromous fish

2017 ◽  
Vol 68 (1) ◽  
pp. 159 ◽  
Author(s):  
W. M. Koster ◽  
F. Amtstaetter ◽  
D. R. Dawson ◽  
P. Reich ◽  
J. R. Morrongiello
Keyword(s):  
Environmental Flows ◽  
Environmental Flow ◽  
Individual Species ◽  
Spawning Activity ◽  
Regulated Rivers ◽  
Potential Conflict ◽  
Effective Delivery ◽  
Environmental Requirements ◽  
Australian Grayling ◽  
Species Ecology

Detailed understanding of flow-ecology requirements for aquatic biota underpins the use of environmental flows as an effective restoration tool in regulated rivers. However, flow recommendations are often overly simplistic and insufficient to provide the necessary environmental requirements for these biota. This is often due to failure to gain and integrate information on individual species ecology and, by using coarse generalisations, about flow-ecology responses. To inform more effective delivery of environmental flows, we investigated spawning responses of the threatened Australian grayling (Prototroctes maraena) to environmental flows over 2 years in three coastal rivers. Spawning activity was highest during within-channel flow pulses, especially during periods of environmental flow delivery. Peak spawning occurred in late autumn and was positively related to flow duration. This result has important implications for environmental flows management in regions where water is scarce and there is potential conflict among multiple users because, for Australian grayling, it is not necessarily the volume of water released that is important, but how the flow is delivered. Our study demonstrated the importance of quantifying flow-ecology relationships via targeted monitoring and research so as to develop appropriate flow regimes, and should encourage managers to examine more critically the logic behind generalised environmental flow objectives.

Constraints on the recovery of invertebrate assemblages in a regulated snowmelt river during a tributary-sourced environmental flow regime

2011 ◽  
Vol 62 (12) ◽  
pp. 1407 ◽  
Author(s):  
Andrew J. Brooks ◽  
Matthew Russell ◽  
Robyn Bevitt ◽  
Matthew Dasey
Keyword(s):  
Flow Regime ◽  
Environmental Flows ◽  
River Regulation ◽  
Environmental Flow ◽  
Regulated Rivers ◽  
Macroinvertebrate Assemblages ◽  
Fine Sediments ◽  
Tributary Stream ◽  
Invertebrate Assemblages ◽  
And Control

The impacts of river regulation on aquatic biota have been extensively studied, but long-term assessments of the restoration of biota by environmental flows and the principal mechanisms of recovery have rarely occurred. We assessed whether the provision of an environmental flow regime (EFR) via the decommissioning of an aqueduct on a tributary stream altered downstream macroinvertebrate assemblages in the highly regulated Snowy River, Australia. Macroinvertebrate assemblages of the Snowy River, reference and control sites remained distinct despite the provision of environmental flows. Invertebrate assemblages detrimentally affected by regulation probably remained impaired due to either constraints on colonisation from the tributary stream (dispersal constraints) or unsuitable local environmental conditions in the Snowy River caused by flow regulation (e.g. high levels of fine sediments, elevated temperature regime) suppressing new colonists or recovery of extant populations. Our study showed that restoration may be ineffective if EFRs are too small to ameliorate local environmental factors constraining the recovery of affected biota. Other barriers to recovery, such as dispersal constraints, also need to be overcome. Successful restoration of regulated rivers using environmental flows requires an understanding of the mechanisms and pathways of recovery, together with identification and amelioration of any potential barriers to recovery.

Emerging mitigation measures and strategies are needed for riverine ecology to ensure sustainable hydropeaking production in Norway 

2021 ◽  
Author(s):  
Jo Halvard Halleraker ◽  
Mahmoud S. R. Kenawi ◽  
Jan Henning L’Abée - Lund ◽  
Anders G. Finstad ◽  
Knut Alfredsen
Keyword(s):  
Biological Indicators ◽  
Ecological Impacts ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
National Database ◽  
Political Agenda ◽  
Regulated Rivers ◽  
Hydropower Production ◽  
Multiple Pressures ◽  
Environmental Requirements

<p><strong>Riverine biodiversity</strong> is threatened with severe degradation from multiple pressures worldwide. One of the key pressures in European rivers are hydromorphological alterations. Rehabilitation of river habitats is accordingly high on the political agenda at the start of UN decade of ecological restoration (2021-2030).</p><p><strong>Water storage</strong> for hydropower production (HP) has severe impacts on aquatic ecology in Norway, with more than 3000 water bodies designated as heavily modified due to hydropower. Norway is the largest hydropower producer in Europe with a huge amount of high head storage schemes. Ca 86 TWh of this is storage hydropower, which constitutes more than 50% of the total in Europe. This makes Norway a potentially significant supplier of hydropeaking services. Flexible hydropower operations are crucial for EUs Green Deal in balancing electricity from renewable intermittent power generation such as wind and solar. </p><p>Many Norwegian <strong>HP licenses</strong> were issued before modern environmental requirements evolved. Few are re-licensed with emerging strategies to mitigate hydropeaking. Still, there seems to be a common understanding of relevant mitigation strategies emerging between many large hydropower producers. For example, flow ramping from hydropower tailrace water with direct outlet into fjords or other lake reservoirs may be less environmentally harmful than outlet into riverine habitat.In this study, we have assessed the Norwegian hydropower portfolio of more than 1600 HP facilities constructing a national database focusing on the knowledge base for assessing potential downstream hydropower ecological impacts. The ecological severity of such flow ramping and the restoration/mitigation potential, may depend on;</p><p> </p><p>About 51 % of the HPs (ca<strong> 80TWh</strong>) have tailrace into shorter rivers (<1 km) or directly into fjords or lake/reservoirs. Many of the largest HPs are in this category (e.g 50 HP> 500 MW). Close to 800 HP might have downstream impacts on rivers (> 0.5 km; about 49 % of all HP, in total of ca<strong> 56 TWh</strong>). Probably <strong>> 3 000 km of regulated rivers</strong> in Norway therefor might need more ecosystem-based mode of HP operation. <strong>Flow ramping analysis: </strong> Ecosystem-based HP operational rules are established in a selection of sustainably managed Norwegian rivers, still with significant baseload production (0.35-0.76 - TWh annual prod). However, eco-friendly mode of operation seems to be rare as our analysis indicate that flow ramping with potential ecological degradation seems widespread in many rivers. Surprisingly, even in many with operational ramping restriction as required mitigation.Our database may be further improved and updated (with e.g. more flow ramping data and biological indicators) and serve as a basis for a national hydropeaking strategy, and hence make more of the Norwegian hydropower portfolio in line with the EUs sustainability taxonomy.</p>

A simulation tool for managing environmental flows in regulated rivers

2015 ◽  
Vol 73 ◽  
pp. 117-132 ◽  
Author(s):  
C.M.M. Steinfeld ◽  
R.T. Kingsford ◽  
E.C. Webster ◽  
A. Sharma
Keyword(s):  
Environmental Flows ◽  
Simulation Tool ◽  
Regulated Rivers

scholarly journals Response of the Snowy River Estuary to two environmental flows

2015 ◽  
Vol 127 (2) ◽  
pp. 28
Author(s):  
Errol J. McLean ◽  
Jon B. Hinwood
Keyword(s):  
Fresh Water ◽  
Peak Flow ◽  
Environmental Flows ◽  
River Estuary ◽  
Environmental Flow ◽  
River Channel ◽  
Salinity Gradients ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Major River

The Snowy River is a major river in south-eastern Australia, discharging to the Tasman Sea via a barrier estuary, with its entrance constricted by marine sands. Since the construction of the Snowy Mountains Scheme, river flows have not been sufficient to maintain the river channel. A program of environmental flow releases (EFR) is returning water to the river to restore the fluvial reaches and is now trialling flow regimes that may also benefit the estuarine reaches. This paper documents the response of the estuarine segments of the Snowy River to two EFRs; the release in 2010 was designed to scour the upper reaches of the Snowy River while the larger 2011 release was intended to extend the scouring downstream. For each release, the effects on the entrance morphology, tides and salinity through the flow peak and recovery are described. Each EFR caused minor increases in depth and very minor longshore movement of the entrance channel, although each EFR had been preceded by a larger fresh flow that would have scoured the channels. The small increase in fresh water inflow in the 2010 EFR pushed salinity contours seawards and steepened vertical salinity gradients. The larger inflow in the 2011 EFR purged the upper estuary of saltwater. After the peak flow, salinity recovery was rapid in the principal estuarine channels but took weeks where poorly connected wetlands could store fresh flood waters. Critical flows for scouring the entrance and purging salinity are estimated.

Application of Methodologies for Environmental Flow Determination in an Andean and a Mediterranean Basin

2013 ◽  
pp. 296-314
Author(s):  
Yesid Carvajal-Escobar ◽  
Ziad Mimi ◽  
Saed Khayat ◽  
Saleh Sulieman ◽  
Wilson Garces ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Significant Variation ◽  
Environmental Flows ◽  
Environmental Flow ◽  
Base Flow ◽  
Point Sources ◽  
Local Context ◽  
Mediterranean River ◽  
Hydrological Indices ◽  
Hydrological Parameter

The demand for sustainable water management has promoted the development of methodologies for estimating environmental flows (EF). In this paper, the EF in an Andean river (Pance, Colombia) for conservation and a Mediterranean river (Wadi-Zomar, Palestine) for restoration purposes is made. Different methodologies are applied given the objectives for each river. The authors used hydrological indices proposed for watersheds with different water regimes and adaptations and validations were made to the local context. These methods allow for estimating the EF at various points in the river and the assessment of disruption scenarios for decision-making. In the Wadi Zomar River, three sampling points were selected. The water samples were then examined for the presence of pathogens. No one indicator or simple hydrological parameter is entirely suitable for all environmental systems and pathogens. In the base flow conditions, the amount of pollutant load varied temporally according to the amount of load from point sources along the Wadi, and spatially with distance from the same sources. Significant variation was observed in response to the hydrological behavior of the catchment. The assessment for the water quality in the Zomar reflects a potentially serious threat to the environment. The results emphasize the need for regulating the seepage effluent from industries and sewage system along the stream.

Managing waterway health in the Goulburn Broken Catchment, Victoria, Australia

2001 ◽  
Vol 43 (9) ◽  
pp. 29-36 ◽  
Author(s):  
W. Tennant ◽  
J. Sheed
Keyword(s):  
Water Resources ◽  
Community Involvement ◽  
Local Governments ◽  
Local Community ◽  
Environmental Flows ◽  
Federal State ◽  
Murray Darling Basin ◽  
Effective Delivery ◽  
Improvement Programs ◽  
State And Local

Historically within most catchments, resource management programs have been planned and implemented in isolation of one another. This was once the case in the Goulburn Broken Catchment, a major catchment of the Murray Darling Basin, Australia. Although only 2% of the Murray Darling Basin's land area, the catchment generates 11% of the basin's water resources. Learning from the past, a cooperative and collaborative approach to natural resource programs has developed. This approach is the envy of many other catchment communities and agencies. Through a combination of “Partnership Programs”, “Operational Initiatives” and community involvement, significant programs have been implemented within the catchment, which will benefit not only the local community but communities further afield. The outcomes of the waterway health program highlight the benefits provided through the establishment of cooperative and partnership resource improvement programs. These programs were founded on the ability of the community to recognise the need for integration, base management decisions on best available science and an ability to work together. Their effective delivery has been provided through the resources provided, to the local community, by the Natural Heritage Trust with matching and State and local allocations. While programs have shown success, challenges still face the community. These challenges include verification and implementation of environmental flows, storage of the catchment's vital water resources, and maintaining community involvement and participation in on-going works programs. The Goulburn Broken Catchment community, with the support of Federal, State and Local Governments, is looking at opportunities for continued improvements in waterway health.

Environmental Flows Legislation and Regulations in Foreign Countries and the Enlightenment to China

2013 ◽  
Vol 295-298 ◽  
pp. 2181-2186
Author(s):  
Chang Chun Chen ◽  
La Chun Wang ◽  
Xue Zhang Cao ◽  
Jie Song
Keyword(s):  
Water Demand ◽  
Aquatic Ecosystems ◽  
Environmental Flows ◽  
Environmental Flow ◽  
International Agreement ◽  
The Enlightenment ◽  
Foreign Countries ◽  
The World ◽  
Key Factor ◽  
Legislative Proposals

Environmental flow is a key factor to protect river ecological system, however, there is no international agreement concerned with environmental flows exclusively so far. This paper demonstrated the importance and urgency of environment water demand in the world and presented summary and analysis of environmental flows legislation and regulations. Europe and other countries have been investigated and compared systematically. At last, specialized legislative proposals were provided for protection of aquatic ecosystems and their environment in China.

Modelling the economic impact of environmental flows for regulated rivers in New South Wales, Australia

2003 ◽  
Vol 48 (7) ◽  
pp. 157-164
Author(s):  
R.T. Jayasuriya
Keyword(s):  
Economic Impact ◽  
Environmental Flows ◽  
New South ◽  
New South Wales ◽  
Water Source ◽  
Regulated Rivers ◽  
Community Based ◽  
South Wales ◽  
Groundwater Aquifers

The management of water resources across Australia is undergoing fundamental reform in line with the priorities identified by the Council of Australian Governments (COAG) in 1994. This includes reforms to the specification of property rights, the way the resource is shared between the environment, irrigators and other users, charges for water use and the operational management of the river systems. In New South Wales (NSW), a series of water sharing plans (WSPs) is being developed for each water source in the State including regulated rivers, unregulated rivers and groundwater aquifers. These plans, which are the mechanisms by which COAG reforms are being implemented, are being developed by community-based water management committees (WMCs). The role of the WMCs is to develop a plan that achieves a balance between environmental, economic and social outcomes. NSW Agriculture has assisted a number of WMCs by quantifying the economic impact of proposed WSP options on the irrigation community. This paper outlines the approach taken by NSW Agriculture to quantifying economic impacts on irrigators in regulated catchments and provides results of case studies in the Lachlan River Catchment which is heavily developed for irrigation.

scholarly journals From an irrigation system to an ecological asset: adding environmental flows establishes recovery of a threatened fish species

2019 ◽  
Vol 70 (9) ◽  
pp. 1295 ◽  
Author(s):  
Ivor Stuart ◽  
Clayton Sharpe ◽  
Kathryn Stanislawski ◽  
Anna Parker ◽  
Martin Mallen-Cooper
Keyword(s):  
Water Level ◽  
Fish Species ◽  
Life Histories ◽  
Environmental Flows ◽  
Irrigation System ◽  
Spatial Scales ◽  
Environmental Water ◽  
Environmental Flow ◽  
Murray Cod ◽  
Riverine Fish

Worldwide, riverine fish are the target of environmental water because populations have declined in lotic river habitats following river regulation. Murray cod is an endangered Australian riverine fish with remaining populations associated with lotic river reaches with instream habitat, including some creeks operated as part of irrigation systems. Our objectives were to develop a life history model, apply the building block method of environmental flows to enhance the abundance of juvenile Murray cod and promote population recovery. From 2008 to 2018 we evaluated changes to Murray cod juvenile abundance before and after implementation of a perennial environmental flow regime that began in 2013. During the first year of the environmental flow, larvae were collected as evidence of spawning. Murray cod abundance can be enhanced with environmental flows that target: (1) an annual spring spawning or recruitment flow with no rapid water level drops; (2) maximising hydrodynamic complexity (i.e. flowing habitats that are longitudinally continuous and hydrodynamically complex); and (3) an annual base winter connection flow. Recognition that incorporating hydraulics (water level and velocity) at fine and coarse time scales, over spatial scales that reflect life histories, provides broader opportunities to expand the scope of environmental flows to help restore imperilled fish species in regulated ecosystems.

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