Property:Lessons learnt
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This is a property of type Text
R
Water board Drents Overijsselse Delta observes that it is important to plan and time maintenance well and to communicate well with water managers. Most notably, the developing vegetation caused the water to smell when water levels were high, so that weeds had to be cut along the entire stream. +
T
Water pollution is a difficult topic to engage and enthuse members of the public about. More people were engaged about the topic when we held stands at already existing events that people would be going to rather than hoping people would attend an event specifically held by this project. We found that making the events aimed at homeowners targeted to families meant that more people attended and we could discuss general water management and water pollution with the adults whilst the children did craft activities. Relating water pollution to wildlife on the estuary (which is a prominent feature locally) meant it was easier to engage members of the public about the topic.
The walkover surveys were a success in gathering information to inform future delivery projects and in engaging partner organisations in Water Framework Directive project delivery.
The quality of the Pollution Prevention Pack was highly regarded by partners including stakeholders from other Catchment Partnerships. Enthusiasm for the packs has come from stakeholders in Devon, Gloucestershire, Northumberland, Derbyshire, Sussex, Shropshire and Bedfordshire. We know of two organisations from neighbouring Catchment Partnerships that are making minor amendments to the electronic version so they can use them locally. +
H
We can provide data to NE to support and inform restoration works. We will continue to work with partners to improve WFD status. +
W
We did not encounter any major issues. Yes there were small hiccups during the delivery side of things (wrong gravel delivered, last-minute change of contractor), but not something that truly endangered the project.
The approach we took - project delivery mainly by volunteers - was so successful that we will endeavour to make that an important part from all future projects. +
S
We have learned a number of lessons:
1. Importance of Bottom up approach and community support for Natural Flood Management. It is impossible to undertake this work on the scale needed to make a difference to both natural processes or flood risk if widespread community support is not given.
2. We think it is important to start work quickly to create momentum and inspire communities that the approach is feasible rather than theoretical.
3. Even small interventions can make a difference quickly in a degraded stream system, creating habitat complexity, refugia, and allowing light into a heavily shaded area.
4. Use local contractors to increase buy-in and capacity for undertaking works.
5. Start at the most upstream location feasible and work your way downstream. Working on smaller water courses has less risk and less requirement for modelling and feasibility work. +
D
We have yet to review the lessons learnt. +
G
We worked with the landowner, built a bespoke design, and with the landowner's support, held an event to share the successes and lessons learnt with other farmers. There was huge value in facilitating a farmer to farmer discussion. +
R
What we have learned so far is the importance of having reliable discharge data, and also the need to target monitoring to measure any specific restoration work being carried out. +
M
When adding gravels to the river bed to previously dredged sectiosn be aware ofg the imapct this may have on flood connection during higher flows. Follwing the addition of gravel the two following winters have experienced very high flwos whith significant prolonged out of bank flows for severals months each winter. In this case thelandowner was ok with this but in other projects this may have become a significant issue. +
B
When planning a large-scale project of this nature, the first consideration should be what is the lowest cost and least disruptive way of achieving the objectives. Previous habitat works have focussed on lowering the floodplain to meet the water surface. This is often costly with excess spoil to move and spread and has a high initial impact on site both ecologically and aesthetically. It can also be very effective to work up projects in several phases over several years to allow interventions to be in and establish e.g channel narrowing followed by gravel introduction. +
W
While the project was successful at stabilizing the bank where it was most at risk (i.e. steep and close to public footpath), the bank poaching caused by dogs has just moved to another location. This should be considered in any similar project that seeks to restore bank that is deteriorating as a result of livestock or recreational activity. Consider where dogs or livestock will next enter the river, and consider whether the river at that point will be sensitive to the pressure. Are there any other unstable banks or important habitats such as spawning gravels that may be impacted? Consider whether fencing or formal drinking bathing points may be required. +
S
With close liaison with permitting and enforcement colleagues it is essential to apply the relevant legislation appropriately.
This is used as a pilot scheme for other projects which are linked with WWF/Waterlife/Coca Cola over the next 3 years. +
T
With this action, an
extraordinary flood was
prevented (the year after
the dam removal) that
would have flooded part
of the city of León.
The realization of this
removal in an urban area
is a great success since it
increases the awareness
of the society because
they will demand this type
of actions when seeing the
results.
The location of the weir
near a bridge forced to
use more costly removal
techniques, which
increased the final price of
the project. +
H
Wood for construction of deflectors was sourced locally and work was undertaken by hand. Therefore the size of deflectors were limited to what could be manoeuvred by hand. Despite their size, careful consideration of the prevailing flow and sediment conditions meant they could be placed to achieve optimum benefit.
In November 2014 some of the wooden posts, used to hold deflectors in place, had to be replaced. The posts were 75 mm diameter and it is thought that the staples and screws used to secure wire to these posts were too large, causing the post to be weakened and split under load. We have since replaced posts with 20 mm re-bar drilled through the deflectors. Post diameter and staple size should be considered when planning how to secure LWD. +
R
Work could not be carried out in section 3 due to the firmness of the riverbed. It is reccomended in the future that the firmness of the riverbed should be tested to ensure habitat improvement works can be carried out.
Install coir matting vegetation at the same time as installing brushwood, we had to rely on individual plug plants when planting. Although plugs are cheaper than matting. +
C
Working with a local contractor Seed and Spur, we were able to complete the works within the timescale and under budget of £750 in addition to SRT staff costs to prepare the consents, engage the business and monitor the work. +
L
You can set back flood defences even in highly constrained locations. In particular the A13 site is located next bridge supporting a major road into London. The steel sheet piling has been removed and intertidal banks have been restored. +
G
cost neutral +
E
expected soon... +
N
implementation was delayed by one year due to difficulties with obtaining permits (due to objections from the local community). It Fryske Gea had to go to court to obtain the necessary permits (personal
communication, It Fryske Gea). +