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B
The artificial burn corridor had little character, with very poor habitat possessing low diversity in species. The restoration project was implemented to improve the environment on the burn corridor and reduce the risk of flooding (to a 1 in 200 year event). During a 2010 flood event the project proved to successfully limit flood waters to designated flood areas.
The works comprised a two stage flood defence scheme with the first stage being a low bund to withhold a 1 in 20 year event. The second stage works involved the construction of clay embankments and sheet pile and concrete walls clad in stone recovered from the park’s boundary wall creating 190,000m³ of flood reservoir storage.
Environmental improvements included lowering artificially raised banks and the concrete channel was replaced with sinuous meanders to restore the watercourse. Wetland areas were created to provide habitat variety. +
O
The artificial side channel of Opijnen was created by opening up groynes along a longitudinal dam. This has led to a flowing side channel which has been extensively monitored for ecological response. This manner of side channel can be used to improve navigation while at the same time restoring characteristic habitat for rheophilic fish and benthic invertebrates. Macrophytes have not shown a clear positive effect in this case.
The river Waal is a major tributary of the Rhine. Near the village of Opijnen a number of groyne fields were closed off in 1984 by the construction of a longitudinal dike. This construction improves navigation conditions for ship traffic on the Waal by directing the flow more towards the center of the channel. This prevents unwanted sedimentation of the deep middle parts of the channel which are used by ships. The site is situated in the outer bend of a meander. By closing off these groyne fields the hydromorphological conditions were altered. Water flow was stopped, leading to static water bodies in the groynes. Also the sedimentation and erosion of the banks was hampered.
National natural and ecology policy led to measures being taken to restore part of the natural flow and dynamics in the channel that the dike had severed. This was undertaken in 1994. To do this without influencing the main channel, openings were made at two points in the dike (entrance & outlet) and between the groynes. This allowed water from the main channel to flow through. In essence a side channel was created. The side channel has a flow during 99% of the year due to the bed level and the bottom sill at the entrance of the channel. The measure was taken in hopes of artificially creating biotopes that no longer exist along the heavilly modified river Rhine.
The project served as a pilot to monitor and analyse the effects. Scientific research was done on the channel to identify if the channel indeed served to (re)create habitat and biotopes that had disappeared due to channelization and artificial alterations of the Rhine and its tributaries in the Netherlands. The primary success criteria in this research were an increase in characteristic wading birds, fish and macro invertebrates.
S
The basic task of water management in coming years in Poland will be measures for decreasing the rate of water runoff from catchment. One of the important measures include the implementation of small natural water retention. It is a method of storage of water to improve the water balance of small river basins and limit losses originating as a result of excess or lack of water becomes widely acknowledged. It is often stressed that small retention is a combination of technical and non-technical measures restoring the natural retention of small river catchments (Burek, Mubareka 2012; EU Commission 2012; Mioduszewski, 2009).
The planned increase in the volume of retention waters was based mainly on small water bodies
(ponds), which is predicted to increase retention by 860 million m3
(4789 reservoirs). Damming of lakes
(620 pcs) is assumed to increase the retention by 263 million m3
, and damming of water in the drainage
system (basic and detailed) is expected to increase it by another 18 million m3
. In total, the national
retention programme is expected to increase water storage by 1,141 million m3 by the end of 2015. It
is estimated that the investments made has resulted in an increase in water retention in the country
by an average of about 15 million m3 per year, although in rural areas, the increase was planned to be
approximately 60 million m3 per year. +
R
The biala river has been restored since 2010 as the aim of improving the habitat conditions for riverine and riparian biota in the Biała valley including the restoration of longitudinal river connectivity, reintroduction of Atlantic salmon population and increasing the size and range of thick-shelled river mussel and yellow-bellied toad populations.
The project encompasses 6 tasks:
1) Removing barriers to water organisms migration in the river
2) Reintroducing salmon population to the river
3) Delimiting the erodible river corridor and establishing conditions for its functioning
4) Restoring integrity and re-colonization of the bivalve population in the river basin
5) Restoring the continuity of amphibian populations in the river valley
6) Restoring riparian vegetation
Technical works includes construction of fish passes at four concrete weirs, re-establishing migration possibilities for river biota, designing fish passes at the location of 10 other weirs, releasing 1,2 million unfed fry of Atlantic salmon, establishing erodible river corridor along 20 km-long sections of the Biała valley, increased area and continuity of riparian shrubs/forest along the river; reduction in the occurrence of invasive plant species in the riparian area
The project is complex approach to restoration of the ecological integrity of a mountain valley corridor, encompassing restoration measures focused on the habitat conditions in the river and riparian area as well as on the populations of selected, threatened species.
Works included: Delimiting the erodible river corridor and establishing conditions for its functioning. +
P
The bypassing of shingle beach material from the Church Norton spit onto Pagham Beach in West Sussex (Photo 1 and Map 1) was carried out in 2009 to quickly address the loss of beach sediment from parts of Pagham Beach onto frontages downdrift from which it could not be recycled.
• Bypassing was seen as an 'adaptive management' intervention that accelerated the expected future natural sediment movement.
• Implementation of bypassing was quicker and cheaper than for beach recharge. +
R
The bypassing water course at the hydropower plant Rheinfelden, on the High Rhine, is the largest fish pass facilitiy of this type in Central Europe. The old hydropower station was a diversion-channel type plant. The new station is a run-of-river power plant. Three fishways are installed, a vertical slot pass at the power house (left bank), the new bypassing river course installed in the old headrace channel(right bank) and a rock cascade pass which connect the tailwater of the weir with the river course.
The main intention of this new river course is to provide suitable habitat for rheophilic species, especially spawning grounds for gravel dependent fish species, for example barbel (''Barbus barbus'') and nase(''Chondrostoma nasus'').
With a width of 40-50 m, a mean gradient of 0.9 % and a discharge of up to 35 m³s-1 the bypass channel has the character of a mountain river. The mean discharge is 16 m3/s and the attraction flow is 15 m3/s.
The aim is to provide a high variety of bottom and flow structures induced by sequences of riffles, bars, pools and single gravel islands. The bed material consists of continuous gravel. In riffles and fast flowing reaches coarser material is provided. A deeper flow path ensures fish passage even at minor discharges. The river banks are characterized by bars, shallow regions, small bays, undercut banks and riparian vegetation. The bypass channel is connected to the weir impoundment with a gentle transition involving several braided channels. The intake structure itself is divided into two sections. One section will be controlled by two gates, the other will be unregulated. The unregulated section will guarantee a constant discharge of 10 m³s-1 in the bypass channel. Additional discharge up to 25 m³s-1 can be provided via the regulated gates in order to provide a dynamic flow regime.
The downstream entrance is designed as a rock ramp with a steeper gradient (3%), thus downstream water-level fluctuations are limited to this ramp; i.e. flow characteristics in potential spawning grounds in the bypass channel will not change. The cross-section at the mouth of the channel is narrowed to provide more efficient attraction flow into the tailrace.
The total cost of the project was 6 milj. € and the by-pass channel cost 4 milj. €. There is no constant monitoring yet, but they have calculated the amount of the fish in the by-pass channel to be 30 000. In the other fish way the number of fish was 3 000.
W
The cantonal city of Basel and the Kraftübertragungswerke Rheinfelden built the Augst-Wyhlen barrage between 1908 and 1912. The plant consists of the Wyhlen power plant on the German bank of the Rhine and the Augst power plant, as well as the jointly managed weir and watergate on the Swiss bank of the river.
Wyhlen hydropower plant gives discharge to the fish way 800 l/s. The attraction flow is 1 m3/s.
For the small turbine there has been installed the nature-like pool pass. Now the fish have the possibility to migrate to the upper streams from both sides of the River Rhein in Wyhlen.
Fish lifts was constructed year 2005. The hight is 16,75 m. The dimension of the fish cage is 2,5x2,5x1,5 m (volume of the tank is 2,15 m3). The operating discharge is 1,2 m3/s and the operating interval is 1 to 3 hours.
At Wyhlen Ryburg-Schwörstadt there is also a new bypass under contruction.
Total length will be 1 150 m. And the total difference in height is 10,7 m. Discharge will be 3,0–6,0 m3/s (small turbine 4,5 m3/s, in total 6 m3/s).
And close to the new bypass there is a new fish way under construction also. Discharge to the new fish way will be 800 l/s and the attraction flow 600 l/s.
There will be two entrances to the fish way (one near the turbines and one further). +
S
The catchment of the Upper Clun and its tributaries is largely unsewered and, although the population density is low, the contribution of septic tanks adding nutrients to the river needs to be better understood. The river is classified to be of high quality but a Special Area of Conservation (SAC) at the lower end is being degraded and there are other signs of freshwater related biodiversity decline. Nutrients play their part, but some of this decline is believed to be due to the deposition of sediment in the riverbed. The river is heavily silt-laden when in spate and this is particularly noticeable in the upper reaches. The steep slopes and high rainfall in the Upper Clun are likely to lead to proportionately high soil erosion and rapid transport with roads acting as conduits and drains as pathways for more rapid transport to the river. This is a community-led and Environment Agency financed review of the state of septic tanks and road drains in the Upper Clun catchment.
Community Engagement - volunteers used to survey householders via face to face interview and questionnaire. Householders with failing septic tank systems were offered expert advice on solutions via consultants. Feedback given to all community through a public meeting. +
The channel is in culvert for approximately 350m either side of Burnbrae Road. This project will deculvert this section to restore connectivity along the South Calder. Upstream of the culverted section, the open river South Calder was historically straightened. This has degraded the channel significantly and a new channel is planned to improve the river's morphology and habitat quality. The project also aims to achieve water quality and land remediation benefits.
Upstream of the project site and downstream of the culverted section, the South Calder has a more natural form and characteristics and the project will aim to mimic these natural processes to achieve the desired post project morphology. +
M
The channel was canalised, embanked, and virtually featureless carrying highland water from upstream across a flat lowland valley. Marsh either side is grazing land designated as SSSI.
Aims of the project:
• To restore the open water characteristics of remnant cut-off channels of the Cefni that were being to be lost through drying and reed/rush/sweet-grass invasion.
• Combined with local restoration of high water tables, these measures ensured that the wildlife interests which gave rise to its notification as an SSSI are maintained and enhanced.
Works carried out:
• excavation of drying relic meanders and other open water areas
• sluices on drains/ditches to raise water levels in summer
• sluices and/or bunds to raise winter water levels
• willow/scrub control and other vegetation management
• improved bank profiles to the many ditches that traverse the floodplain +
F
The concerning weir was small and it served to supply irrigation communities in the area. In origin, the weir was of an approximate height of 40 cm. However, over time, an
erosion was generated downstream the obstacle so its height increased to 1.5 meters
and the weir became impassable. This was a problem since the community of fish in
the river is very varied and this obstacle became a serious problem for its movement
through the river.
Among the variety of existing fishways, in this particular case the chosen option was
the installation of a rock ramp. This type of device mimics the natural conditions of the
river. Usually have an inclined plane with a slope always ≤ 10%, in which blocks of
stone of considerable size are inserted.
The advantages of this kind of devices are:
- It offers better conditions of passage (both upstream and downstream).
- Its appearance is better integrated with the environment.
- It allows the evacuation of flows (including ecological flows).
- It does not alter the structure of the obstacle.
- Low maintenance cost.
On the other hand the disadvantages are:
- It requires more space to be built.
- It needs more flow to ensure their functionality.
- It is only applicable to obstacles with small-medium heights (less than 2.5 m).
In this case, the Najerilla River presents marked contrasts of flow between high and
low waters, so that it was proposed to make two sections of the fishway: a deeper
central ramp of about 10 m wide and two shallower lateral ones of 4 m wide each.
Stone blocks of about 1 meter diameter were placed so that no channels were formed
where the water reaches a high speed and impedes the ascent of the fish. Finally,
gravels have been embedded in the surface of the ramp in order to increase the
roughness of the ramp bottom. The slope of the ramp was 5% +
T
The creation of six SuDS in the Salmons’ Brook Catchment will improve the water quality in the Salmons’ Brook and tributaries, along with biodiversity and amenity value of the sites. The physical creation will be just one success - we hope that this SuDS project will increase knowledge of the role of SuDS and create a wider debate within East London. +
H
The defences around the Humber Estuary are affected by erosive forces as a result of strong currents and wave actio. These erosive forces cause damage to the defences and over time undermine the stability and integrity of the defences. If not addressed these defences are at risk of breaching, potentially causing significant flooding and risk to life. The Humber Estuary Erosion Protection Programme aims to remediate and manage the erosion caused to the defences. The programme is supported by the Defra-approved Humber Flood Risk Management Strategy. Alongside erosion protection works, the project also aims to achieve Water Framework Directive objectives through the design of schemes that deliver benefits to the environment.
The Humber Estuary (Map 1) is home to 921,000 people of whom nearly 400,000 are at risk of flooding, as are important industries, 32,500 business and a significant agricultural sector. The area hosts some of the highest value assets and critical infrastructure in the country, including power stations and refineries, the country’s largest port complex, a petrochemicals industry worth £6 billion per year and approximately 115,000ha of high grade agricultural land. There are some 230km of flood defences protecting the area to various standards of protection. +
T
The demand to fish the Wye was such that in the mid-20th century it was a case of "Dead Men’s Shoes". Beats were extremely valuable and anglers paid handsomely to fish the better ones. The pressure on catching fish was also high - all methods were used and beats seemed to accommodate many more rods than they do today. In addition, ghillies were employed to ensure catches remained high.
When the salmon runs collapsed in the early '90s, it was sudden and dramatic for all, except the lower beats. Lots of fishing suddenly became available but there was no means of putting anglers in touch with it. In 2003 we contacted all the fishing hotels on the upper Wye and found only one (owned by a keen angler) who was able to accommodate visiting anglers. The economy linked with fishing had all but collapsed along with most of the associated jobs.
In order to meet the requirements of EU funding, it was essential to show that our work and subsequent improvement to fisheries benefitted the rural economy, either with direct employment or by boosting revenue. We needed a scheme that did just this and at the same time enable us to calculate the extent of these benefits. The launch of pHish and some post Foot and Mouth funding (Adfywio) to get visitors back to Powys were the drivers that created the 'Upper Wye Passport' in 2003.
WHIP, our first project, gave us the opportunity to market restored trout fisheries and by combining neighbouring farmers' ownerships we were able to make beats of a worthwhile size. This gave the farmers some real incentive to look after their tributary. Many also had B&Bs that could be filled by anglers during the less popular months of the year. Our first Roving Voucher (now Wild Stream) scheme was on the Edw, Clettwr and Duhonw. Simplicity was the key factor: fishers bought vouchers, posted them in the beat box and enjoyed a day’s wild trout fishing. Later we added fisheries on the main river, giving rise to the "Booking Office". Then came the Usk, Lugg, Arrow and Monnow; and later reservoirs and still waters.
In 2007, The Rural Enhancement Scheme funded fisheries infrastructure improvements in Herefordshire - paths, huts and bank repairs. The project added another 35 fisheries including, for the first time, coarse fishing on the middle/lower Wye. An online facility was added making out-of-hours bookings possible. A webcam on a gauge heralded a novel way of providing information on water conditions. Now there are nine spread throughout the catchment of them.
In 2003, the first year, 13 main Wye and tributary beats generated a modest £1,845 in fishing sales. Ten years later this was over £250,00 We have over 160 fisheries on board, including some outside the Wye and Usk and some of the area’s top still waters. We calculate the Passport to be worth over £1.3 million annually to the rural economy. We are able to cover its running costs.
How it works
The Passport is made up of two distinct elements:
Our "Wild Streams" focus on the wild trout fisheries created by our habitat restoration, while our "Booking Office" (telephone and online) has been created to take day, week and season reservations for salmon, trout, grayling & coarse fishing on the larger and more established fisheries.
B
The demolition of the San Martín or Bera Dam, 2.85 m high and 102.84 meters long, was carried out. It is the third obstacle in the Bidasoa River from the sea. The works begin on 08/29/2016 and conclude on 10/4/2016 The following actions were carried out during the works:
* Access to the work, cofferdams and conditions. Clearing and clearing of vegetation
* Demolition of the structures (weir and plant intake) and in situ valorization of the materials as fill.
* Regularizing and conserving the gravels of the riverbed.
* Repair of accesses and revegetation of the affected areas +
M
The development of the site is hugely constrained by flood risk, the development should removal all concrete banks and fully restore the channel, through this there is significant opportunity to reduce the risk of flooding to the surrounding areas, thereby enabling development. The areas which do flood can provide significant amenity and recreational value to the public. Site is current a poorly used industrial site, its outlined for development of 5,000 homes in the Enfield Local Development Framework, as part of the London, Stanstead, Cambridge Growth Area. The Pymmes and Salmons Brook confluence is located in the development, and the Lee Navigation runs through the centre of the site with the Lee Flood Relief Channel on the eastern boundary. All of the rivers are in poor condition and generally have concrete banks. +
V
The dike built in the 80’s after the canalization works carried out in Arga River was removed to recover the natural floodplain in one of the tributaries’ confluence: Vallacuera stream.
The main objective of this project is to restore the river Arga natural floodplain by removing the dyke and increasing the fluvial territory. There are other secondary objectives: to increase the quality of habitat in Community Interest Areas, with special attention to European mink (Mustela lutreola); creating new habitats for otter (Lutra lutra) and European turtle (Emys orbicularis); quality improvement of habitats 92A0 (willow and black poplar plantation) and 92D0 (tamarisk plantation); spatial planning for cattle.
The project has a total budget of 138.840,25€ and is financed by GERVE-LIFE project, INTERREG GIRE project, "Gestión Ambiental, Viveros y Repoblaciones de Navarra, S.A." and Government of Navarre.
Construction new habitats for otter (Lutra lutra) and European turtle (Emys orbicularis). +
R
The ecological value of the River Stour between Great Bradley and Little Bradley is limited by three key factors: poor water quality, control structures and the periodic flushing of large volumes of water through the reach for the Ely-Ouse transfer scheme. Working in partnership with landowners, the Dedham Vale AONB and the Stour Valley Trust this project focused on creating those habitats that are currently lacking. Two kilometres of river habitat was enhanced with fifty woody debris structures installed to create flow diversity and habitat for fish. Large woody material (provided by landowners) was used to enhance the ecology of the River Stour by amplifying natural processes and creating habitat. A second phase of work involving riparian tree planting is planned for 2016. +
The ecological value of this stretch is limited by three key factors: poor water quality due to agricultural run-off; barriers to longitudinal connectivity in the form of water-level control structures associated with the Ely-Ouse Transfer Scheme; and the periodic flushing of vast quantities of water through the reach due to the Ely-Ouse Transfer scheme. As a result large sections of the river here are dominated by epilithic and floating algae, which are prevalent in areas of slow-moving water. Several frogs were also seen in such areas, alongside invasive, non-native American signal crayfish.
The scheme focused upon maximising the habitat diversity of the river with the view that water quality and quantity issues can addressed at as later date, either as part of or separate to this project. In particular the scheme concentrated upon creating those habitats that are currently lacking within the river. In total 94 woody debris features (including flow deflectors, log jams and brushwood shelves) have been installed by EA and AONB Project staff and volunteers. Using large woody material had the dual benefit of instantaneously increasing oxygenation and flow diversity whilst simultaneously adding structural complexity and cover. Flow deflectors (large pieces of natural wood) were used to accentuate sinuosity in areas that already exhibited meander initiation and for encouraging bed scour in reaches that were comparatively straight. Flow deflectors were orientated downstream at an angle from the bank between 30° and 45°. The length of the deflectors varied but ideally each structure typically occupied between 50-75% of the channel width. Where possible, deflectors were installed on alternating sides of the river to increase channel sinuosity. The distance between deflectors averaged around 25m longitudinal river length, although this varied according to local conditions. Flow deflectors were placed upon the bed of the river and built to varying heights so that different deflectors are effective under different flow conditions. The reasons for using wooden flow deflectors are manifold. Most broadly, reintroducing woody-material to a river creates variations in flow velocity and depth. Diverse flows create diverse habitats, such as slow-flow pool areas where fish can rest when migrating upstream. Variations in flow also create variations in fluvial geomorphological processes, with flow deflectors often being the instigator in the development of erosion. The physical structure of flow deflector installations can also have benefits, providing an important refuge for fish and other in-stream organisms where they can avoid predation. Increased channel roughness and the resultant fluid turbulence through reaches containing flow deflectors often increases the concentration of dissolved oxygen in these sections, further improving fish habitat. More specifically, flow deflectors can be used to narrow the river channel and encourage the development of berms in river reaches that have been over-widened. Artificial log-jams perform a number of functions. Firstly, the localised backing-up effect caused by the jam is likely to force fine sediment to fall out of suspension and accumulate upstream of the structure, thereby reducing its entrainment downstream. Secondly, the water falling over the log-jam may generate a small scour pool from which gravel is excavated and transported downstream to create further features. This creates a habitat in itself, as well as facilitating bed scour and landform creation. Thirdly, the log-jam oxygenates water, provides a refuge for organisms and creates a permeable barrier between two distinct ecotones (the slow-flowing, backed-up upstream habitat and the fast-flowing, slightly derogated downstream habitat). All log-jams were constructed of wood that spanned the entirety of the channel. The maximum height of the log-jams was no more than 20cm above the existing bed level. Where possible the jams were constructed of a single piece of large wood, cut to the dimensions of the channel. All of the log-jams were secured in place using vertical stakes driven into the bed of the river using a post driver, mallet or digger-bucket tool. 4ft and 6ft oak were used construction, whilst some stakes were made from local tree branches. Vertical and horizontal pieces of wood were secured together using 100mm and 150mm timber screws. The sides of each log-jam were dug into the banks of the river where possible. All of the aforementioned measures were taken to ensure the maximum environmental benefit whilst still securing the structures.
E
Elimination of a pond along the Erve River and conservation of the historical heritage in Sainte-Suzanne-et-Chammes +
The existence of numerous weirs in the Erve is the main disturbance in that they separate fish populations, modify aquatic habitats and impact sediment transport.
The reservoir in Sainte-Suzanne had become filled with up to two metres of mud and the stagnant water made the site less attractive for anglers and the public.
In 2009, the Contract for the restoration and maintenance of the Erve proposed the elimination of the two gates and the resulting reservoir. However, the proposal did not make it to the actual project stage.
In 2010, the towns of Sainte-Suzanne and Chammes (that became a single town in 2016) and the Coëvrons intermunicipal board decided to restore the Grand-Moulin by creating a leat in order to conserve the town’s historical heritage and use the site as a showcase and an educational facility.
The project was accepted by the Departmental territorial agency on two conditions:
• that the water-intake structures be passable by aquatic fauna and comply with regulations concerning the minimum biological flow;
• that the two flap gates and the reservoir be eliminated as compensatory measures, particularly given the fact that the excessively high water level would have hindered operation of the Grand-Moulin (overrunning of the wheel).
The project started in 2010 with the emptying of the reservoir, very progressively in order to limit the outflow of the fine sediment. The flap gate and the concrete spillway of the reservoir were then removed. Thanks to these two operations, the mud in the former reservoir stabilised and the river reformed its bed very naturally.
In 2012, the second flap gate located upstream and an obsolete, wooden dam located next to the pumping station were removed.
The two flap gates were replaced by two distribution structures, i.e. rock chutes with macro-roughness surfaces evenly distributed. These structures maintain the minimum discharge in the natural riverbed. In parallel, side leats were created to supply the flume of each mill via buried conduits.
In the former reservoir, the river was left to its own devices in order to produce a natural riverbed in the sediment. In 2013, part of the mud was nonetheless spread on a slight slope at the outlet of the Grand-Moulin tailrace in order to improve the stability of the zone. The banks were planted.
This project was a chance to reconcile ecological restoration and the conservation of the historical heritage (a “showcase” site). The local population has rediscovered the Erve River. A set of walking trails has been created and fly fishing is now practised in the lotic sections. The Grand-Moulin has been restored and now serves to welcome the public to an exhibition on the various uses of water as a driving force (grinding flour, paper production, hydroelectric generation).