Afon Irwch Rehabilitation Project

The scope of the project was to improve the habitat for spawning salmonids and for other vulnerable wildlife such as voles and bats by creating a buffer zone on each bank of the stream. Serious bank erosion required remedial action and a man made; impassable weir was to be removed. The Afon Irwch is an important salmon spawning stream flowing into the Afon Conwy upstream of the Conwy Falls fish pass. It also has a good stock of wild brown trout and loach but has suffered in the last from random sheep dip pollution incidents. A habitat scheme had been developed by EAW over ten years ago but this required serious repair and other work due to four incidents of serious bank erosion partially caused by fallen trees. The original scheme had a length of just less than 1 km but a weir constructed as a smolt trap effectively barred all upstream migration. The weir was sited about 200 metres below the top of the scheme. Above the scheme for about 1 km lies a SSSI where the banks of the stream have been protected from damaging grazing by the construction of stock proof fencing. Removing the weir would open up another 2 km of good spawning habitat. Water quality monitoring by EAW staff has controlled the historical pollution incidents and the stream supported good populations of invertebrates and juvenile fish. The land surrounding the stream is owned by the National Trust and is farmed by two tenant farmers, one participating in the Ty Gofail scheme.

A Site Management Plan was drawn up together with Land Drainage consent documentation and submitted to EAW for approval. Large scale site maps were produced detailing all the proposed habitat improvements. An initial costing was produced using benchmark EAW costings and three approved contractors were identified to quote for the habitat work. Site visits were made with the three contractors to review the proposals and during each visit; good ideas to improve the outcome of the scheme were volunteered by all three contractors. A final RFQ was developed incorporating these ideas and submitted to the contractors. Detailed quotations were prepared by the contractors including Health and Safety and utility plans. The lowest quotation was reviewed against the RFQ and a final site visit made with this contractor to ensure that all aspects of the required work had been included in the quotation and that this was a fixed price contract. The selection of the contractor was approved by EAW and a site visit was arranged to brief the farmers and a representative from the National Trust. Agreement was gained from the National Trust to contribute to the scheme in terms of removal of four fallen trees inhibiting the water flow and to undertake selective pruning and coppicing of bank side trees and bushes at their cost. A request was made to Conwy County Council to contribute in some way top the scheme but this area is outside their jurisdiction as it is National Trust land.

Following approval of the quotation, a final site visit was made with the contractor and the EAW Scientific Officer to ensure full agreement on the scope of the work. Challenge Fund money was paid to the Rivers Trust at this point by the Association of Rivers Trusts and this was banked and reserved in the accounts for completion of the scheme.

A number of site visits were made to review progress during the habitat work and a final inspection was made on completion of the work following meetings with both farmers to ensure their approval of the work undertaken.

The contractor invoiced the Clwyd and Conwy Rivers Trust exactly in line with the approved quotation even though additional work had been undertaken at the contractors cost. The invoice was paid promptly in full by the Rivers Trust.  

Detail of work undertaken.

The work undertaken was in line with the SMP and was primarily renewing fencing on both banks of the stream to ensure a protected buffer strip against grazing. A drinking gate that had silted up due to minor river bed change was replaced by a drinking trough utilising mains water supply from a nearby barn. Additional swing gates were installed towards the top of the scheme creating two drinking points enabling an additional 100 metres of bank to be fenced. This extended the scheme to meet up with the already fenced SSSI.

An impassable concrete weir was breached enabling migratory fish to obtain upstream access opening up an additional 2km of good spawning habitat denied to the fish since the weir was constructed.

Significant work was required to repair banking suffering erosion. The worst example required stonework and bank re-profiling whereas the other instances were repaired by willow spiling and the removal of fallen trees which were diverting the stream into the bank in high flows.

Some coppicing of willow around the stream was done to allow more light into certain stretches of the stream ideal for parr habitat and a general tidying up of overgrown trees was conducted by volunteers.

Financials

Final quotation received from contractor – £11144.30 plus VAT

Original estimate of CCRT contribution to the scheme – £1271.61

Final invoice from the contractor – £12815.94 inc. VAT at 15%

Final contribution from CCRT – £1550.71

Lessons learned.

Overall, the concept of using a real habitat scheme as a training exercise appeared to work very well, minimising resources from EAW and maximising the practical experience to the Trust in how to plan and execute such schemes in the future. The importance of getting the landowner and tenant farmers involved and onside early on in the project minimised any disruption to the smooth execution of the work programme. Using pre-approved contractors and getting guidance from EAW staff on likely costing levels (for example cost of stock proof fencing per metre) was very helpful in developing a budget and in managing the contractors to a high value result. Although full adherence was made to EAW guidelines on H&S and utility planning, a less prescriptive approach to management of the contractor was felt to have saved costs for both parties.

The insistence on a fixed price for the work and ensuring no specification creep throughout the work programme ensured that the programme came in exactly on budget.

Acknowledgements

The Clwyd and Conwy Rivers Trust would like to acknowledge the following:

i) The concept of the Challenge Fund where Rivers Trusts could learn in a controlled way how to initiate and manage habitat schemes was particularly valuable to the Trust enabling us to learn in a “hands on” fashion with a real scheme compared to theoretical workshops.

ii) EAW staff contributed significantly to the scheme through their expertise and experience ensuring a high quality plan of action. Good relationships were built between the Trust and EAW which will be invaluable in the development and implementation of future schemes.

iii) National Trust staff were very helpful in planning and gaining assent to the habitat scheme and contributed valuable resources at no cost in removing fallen trees from the scheme. This work saved £750 compared to what the contractor would have charged for the work.

iv) Three approved contractors with significant experience in working with EAW were chosen to quote for the work. All three brought a number of high value ideas to the original plan and these were incorporated into the scheme prior to final quotation. These ideas saved cost to the Trust and minimised Challenge Fund costs.

v) The two tenant farmers were extremely cooperative recognising that in exchange for giving up a little land for the buffer strips they would have significant lengths of fencing repaired or replaced at no cost to themselves. Both farmers agreed to monitor the fencing and to make minor repairs themselves to the fencing. Equally they promised to inform the Trust in the case of any severe damage to the habitat scheme fencing.

Roger Thomas

Treasurer and Trustee, Clwyd and Conwy Rivers Trust  19/10/2009