Property:Lessons learnt
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S
Strengthening associated biodiversity of habitat 92A0 and control of Invasive Alien Species in the Segura River (LIFE + Ripisilvanatura) +
The project has contributed to the control and monitoring of Invasive Alien Species (IAS) in the study area, mainly exotic Galapagos, as well as the replacement of vegetation on riversides of the Segura River from non-native to native. During the project, different trial management techniques have been carried out for the eradication of giant reed (Arundo donax) and exotic Galapagos (Trachemys scripta). The exotic Galapagos and other exotic species specimens captured during the surveys have been transferred to the Wildlife Recovery Center for management.
The implementation of the different actions has been developed through the participation of volunteers involved in the project. They have contributed to the plantations, removal of IAS from the river, installation of bat boxes and riparian birds banding activities.
The immediate occupation by riparian vegetation returns the river to its natural condition. Among its multiple benefits this status does not promote the spread of fires and gives shelter to numerous native species.
Another achievement of the project has been the raise on awareness among the sectors involved in animals’ sale. Formative talks about the impact that IAS have on rivers have taken place along the project term to put across the message to actual owners and future buyers. +
A
Assessing the habitats outcomes of Floodplain Forest restoration: the case study of the floodplain forest at the Ouse Valley Park +
The project has increased the capacity and flood retention capacity of the floodplain by removing a volume of around 700,000 tonnes of mineral reserves. Some of this volume has been replaced by standing water but under non-flood conditions the standing water lies at lower level that the former ground.
The project has also created better connection between the River Great Ouse and the pre-existing and new channels that have been created in the site. As the river level rises, water can flow into the site (i.e. floodplain) via these channels, thereby receiving floodwater that would previously have put pressure on more developed/built-up areas further down the Ouse Valley, such as Newport Pagnell which has a number of known flood risk areas near the River Ouse.
The complex of channel sand low-lying landforms within the site, including gravel banks, sand bars and small islands provides a varied floodplain habitat that will mature into a diverse ecosystem supporting a wide range of plants and insects, amphibians, birds, fish and mammals such as otter and water vole. The habitats within the site will also contribute to improving water quality by taking-up waterborne nutrients as water passes onto and through the site.
The Parks Trust will operate and maintain the site as a nature reserve open to the general public. This will enable the local community and visitors from further afield to experience the diverse floodplain forest habitat and the wildlife it attracts.
A further benefit of the project is that under the Trust’s charitable remit, the income it received from the gravel sales form the site have been reinvested back into the establishment and care of this environmental project.
With the involvement of Cranfield University, the floodplain forest will be more widely promoted as a case study in habitat creation and restoration techniques and as an on-going subject for scientific monitoring and research. In summary there are a range of ecosystem services provided by the floodplain forest: cultural, regulating and other services.
The project was severely delayed due to a combination of Covid-19 and wet weather, there were also issues with securing planning permission due to the large number of stakeholders involved. +
D
The project won the CIWEM (Chartered Institute of Water and Environment Management) Living Wetland Award 2011 - the project showed what can be achieved when public, private and community groups work together. The project has helped to enhance biodiversity (12 hectares of new habitats have been created), improve flood storage capacity and provide a community resource. +
R
The realignment work has demonstrated the effectiveness of the soft engineering principles that were adopted in preference to hard artificial river banks. New section of the river is indistinguishable from the adjacent reaches. The use of willows has proved successful. +
The removal of the Robledo dam stands out as an example of participatory
management, in which the importance of administrative coordination between
different social agents is evidenced.
The Robledo dam removal will promote the recovery of altered river processes as a
consequence of the construction, exploitation and abandonment of the dam. It will
therefore contribute to the improvement of the ecological status of the Cofio River
and the native fish populations in this river.
A monitoring program was
carried out after the dam
removal (in August 2016)
showing environmental
improvements in the river
after the removal. The
importance of performing
this monitoring before
and after the dam
removal is emphasized in
order to quantify the
effects that this type of
actions have on the river. +
L
The removal of this dam is an example that the performance of these actions, together
with the availability of an adequate flow, generates good results in a short period of
time.
It will be the river with its high flows that finally does the restoration work. The river
mobilizes the sediments naturally the year after the removal +
S
The result of implementation of the small retention program has shown that it is a good and effective
method to increase the ability to retain water in the small river basins. Construction of small water
reservoirs and weirs on ditches and creeks and restoration of drained bogs can limit the fast outflow
of precipitation and melting water from the catchment.
Despite their low capacity, they can be an important part of the floods protection system, particularly
on watercourses experiencing rapid (flash) floods.
Apart from the improvement of the water balance of catchments, small retention objects perform also
various economic functions, mostly on the local level, such as: small water power engineering,
breeding of fish, source of water irrigations in farming and forestry and also in recreation.
The farmers are the most imported persons, who can implement the idea of small natural retention
measures on their lands. Considering the great diversity of small retention measures, plans for small
retention measures should be kept flexible, and should be adapted to the local context. However, an
overarching framework ought to be developed.
This includes:
- the simplification of procedures for obtaining permits for the construction of small water reservoirs that capture drainage water;
- technical and organisational help for small investors (farmers), who undertake some retention measures;
- proposals for legislation requiring the inclusion of certain small retention issues in investment projects;
- financial assistance and the conditions for granting depending on the type of measure;
- identification of the institutions responsible for conducting training and information on issues of small retention.
Based on this overarching framework, small retention measures should be implemented. The strategy
of implementation should include mainly stimulating activities that will be undertaken by different
individuals or legal entities.
The idea of the Natural Small Water Retention Measures (NSWRM) is consistent with the Natural
Water Retention Measures (NWRM), an initiative encouraged by the nature protection specialists.
Natural Water Retention Measures are limited to tasks aiming at restoration of the natural water
retention capacity of catchments. Active human involvement in maintenance and exploitation of the
existing water systems has not been planned. According to the definition of NSWRM, it has been
assumed that only small hydro-technical investments (e.g. small damming reservoirs, damming on
water courses) will be implemented. Also, implementation of new methods of exploitation of water
systems including drainage and irrigation – drainage systems in river valleys has been planned.
G
The results are plain to see. Cumulative benefits.
The video footage shows how the angle of the weir originally directs flow to the inside of the bend. Once removed a more natural flow to the outer bend is established, with large sand and gravel deposits on the inner bend quickly burying the weir remains. The river quickly thins its width at the weir site. This also happened at the Gigg Lane weir site further upstream. One difficulty highlighted by this work is knowing just where to go to collect good data. It became evident that a large amount of erosion occurred at the top of the upper weir, an area that we were not monitoring. By focussing on the events close to our own intervention we saw little of what happened further upstream.
Problems with camera theft for time lapse work. Cameras for the Irwell Rivers Trust considrered disposable and data valued more than equipment. +
M
The results of this monitoring will help the conservation managers to decide which hydraulic calendar(s) should be applied in the future to achieve the objectives of their management plan. +
H
The rivers of South East Wales have an industrial past and were considered dirty and polluted and were therefore abused. The heavy industry has now gone and the rivers have improved drastically, however local people don’t all ways see this and continue to abuse the rivers by dumping litter and rubbish as the think it won’t matter. Healthy Rivers has lead the campaign on this issue by promoting the river habitats and encourage people to change their behavior.
River restoration is physically demanding and requires volunteers to work hard but Healthy Rivers has been fortunate in finding a team of excellent and extremely hard working volunteers.
The weather in South Wales is unpredictable and rain can disrupt river restoration projects or cause unexpected floods which wash away partially finished projects. However Healthy Rivers has always been able to overcome these difficulties. Working in the river does not always go to plan, the river is a dynamic system so Healthy Rivers staff have had to become efficient at over coming difficulties and problems. +
The road inlet designs had to be amended to capture water running along the gully with a road section cut out to allow a deep enough fall into swale. This has been rectified and the majority of run off is now entering the swales as designed.
The SuDS features are currently drier than anticipated. The resilient sedges are thriving, as are unwanted terrestrial plants. This has additional maintenance implications until replanting of edge species next spring.
Originally a much larger wetland was planned at this site to clean water in the stream. However the project had to be significantly scaled back as we were unable to provide data needed to the EA to approve the scheme, as collecting this level data would have been prohibitively expensive. It would be better in future to allow for longer lead time on the project and budget far more for pre-project monitoring, however in this case it is still unlikely that we would have been able to fund the data required. Monitoring of schemes such as the Salmons Brook Healthy River Challenge is imperative to provide proof that SuDS are a positive element in the toolkit of approaches to tackle urban diffuse pollution. +
E
The same integrated project team has worked on five separate flood alleviation schemes protecting four communities in Moray under the banner of Moray Flood Alleviation. These schemes represent an investment totaling £180 million over a fifteen year period. This has been key to the success of the project.</p>
<p>The project team operates a “continuous improvement” philosophy, using regular lessons learnt workshops to ensure that time and money is not wasted on avoidable mistakes in the future. Over the course of the project the team has developed a collaborative and efficient way of working. Currently the project is set to come in £10 million below budget. Four of the five schemes have been completed on time with Elgin scheduled to finish on time this year, 15 years after the start of the project. The project team has been co-located in the same open plan office throughout the scheme’s development and delivery ensuring matters are discussed easily and decisions are made quickly.</p>
<p>During the development of the design for the scheme, the implementation of the Water Framework Directive was in its infancy. Working closely with SEPA, the team were able to predict the implications of the Directive and design a scheme which complemented the requirements. Meeting with SEPA on a monthly basis has resulted in a sound relationship where issues have been discussed and resolved promptly.</p>
<p>The Elgin scheme has been shortlisted for the ACE/NCE 2015 Outstanding Achievement Award, which recognises schemes that have made a contribution to the reputation of consultancy and engineering. The team has also twice been commended by The Saltire Society at their Awards for Civil Engineering; in 2010 for the Forres FAS for a <i>“well managed and well executed FAS, constructed with high regard for the environment”</i>, and in 2012 for the Rothes FAS for <i>“the co-operation, goodwill and ingenuity demonstrated by the team, coupled with the response elicited from the community.”</i></p>
<p><i>“In more ways than one our community has been given a new lease of life and features have been created that complement the authentic architecture and public face of our village.”</i><br>
Rev Bob Anderson, Rothes Parish Minister</p>
<p><i>“I challenged the team to deliver flood alleviation and complement the environment. My measure of success was that the Scheme should be “invisible” and prevent flooding. Not only was the challenge met, but the Scheme was delivered ahead of programme and under budget. The team excelled and the outcome is very pleasing.”</i><br>
Peter Haslam, Moray Council
T
The sections of river that have been restored demonstrate the contrasting approaches of contractors working on different sites (see Image Gallery). The extent of channel narrowing and restoration works take into account varying views of the landowners, the aspirations of the fishery and the requirement to improve the SSSI. +
B
The sites were important for overwintering birds: teal, shelduck, tufted duck, wigeon, gadwell, shoveler, pintail, little grebe, common whitethroat, sandmartins, oyster catchers and linnet. Peregrine falcons also use the site.
Barking Creek is recognised as a valuable feeding and refuge area for a variety of fish species, flounder, eel, smelt, sea bass in both their adults and juveniles life stages. These utilise the full range of sub, intertidal and saltmarsh habitats for foraging and refuge.
creekmouth should not be located in the direction of the prevailing wind or litter can accumulate. +
N
The situation in the small urban Haukåsvassdraget is unclear. It will take time to achieve safe and stable good ecological conditions. Breeding and cultivation of freshwater pearl mussels is already a success. In order to succeed in returning mussels to the main river, water conditions must be improved. Supporting nursery habitats could supplement the conservation work. The mussel habitat at Haukås is an important trial project. +
L
The sluice at the Wet woodland presented some issues post project, with an unacceptable level of water loss through the frame. This was rectified and is now operating at a normal level. However, some thought must be given to the purpose of the sluice and this should inform the design of the sluice. Holding water back requires a strong but not particularly flexible structure.
Any back channel is relies heavily on the correct levels being established, this relies on understanding the local conditions i.e. any local impoundments this may not be easily recognized so early and often discussions with the EA or the local Drainage board are necessary. +
R
The success of the defined measures was hampered by three principal factors, firstly failure to engage local landowners early in the programme; the timing of key tasks, such as planting riparian trees; continued difficulty to control sources of environmental disturbance, in particular serious and continuous point pollution from animal husbandry. Consequently fish assemblages in all stream reaches were still dominated by aliens and highly tolerant species, and native cyprinids were low abundant or absent, revealing the fish index of biotic integrity a low environmental quality. +
L
The technique of installing Large Woody Debris at this site involved digging a trench securing up to a third of the limb in the trench with the remaining in the channel. By using the thicker end of the limb in the trench it left only the thinner branches in the river.
Ideally the wood shoul dbe as large as possible when in the river to ensure it will be long lasting and have as big an impact on the flows lcoally as possible. +
P
The timescales involved from conception to completion were longer than anticipated. The site presents a range of environmental sensitivities and land uses that required further consideration as part of the planning and physical works processes. +