Building the boardwalks

During the week of 1st February 2015, R. J. Clarke, the local landscape contractors selected by The Friends of Pilley Bridge Nature Reserve (PBNR), installed the board walks and footpath bridges at the Nature Reserve. The works were undertaken by a 3-man team using machinery including an excavator and a dumper. The on-site works were completed in a full week (Monday 8am to Friday 5pm), and there had been considerable preparation and collation of the materials beforehand. The works were supervised on-site by a member of the Friends-of group who had specialist knowledge of landscaping, and of the repair of farm dams in Zambia. Approximately 20 hours of supervision was provided throughout the week because frequent decisions were required as the job progressed.

The Friends-of group had had the good fortune to be offered a job lot of pre-used, grey, plastic, boardwalk sections which had formerly been used at Coombe Hill Nature Reserve, by The Gloucestershire Wildlife Trust. In the floods two years ago the walkway which they had formed had been washed-away and the damage sustained to it was such that the sections of which it was comprised were no longer suitable for use other than on a smaller scale project such as this.

As planned and drawn-up by MHP Design, Chartered Landscape Architects of Cheltenham1 the works comprised the removal of parts of the existing ad hoc dam (principally the water-side edge which has been subjected to wear and which had had to be reinforced from time-to-time) and its replacement by a continuous oak board. This was then sealed into the existing structure with clay which was excavated from a location close to Pilley Bridge and brought-in by dumper.

The 1.2m-wide boardwalk was installed across the full width of the dam, and on the south side (the right looking upstream) an additional 5m section was installed along the edge of the pond. This additional section (“the return”) now gives access to a greater area of the water, and also to the upper parts of the pond which had been largely inaccessible to all but more-able scramblers until then.

It was decided to install the return in such a way that its line reflected the slight, convex curve of that side of the pond. The contractors successfully installed the rectangular plastic sections with a slight angle in the centre of the run, which was challenging but has proved to be visually most effective.

A tractor-mounted auger was used to make holes for the wooden posts of English Oak (15cm x 15cm) which form the foundation of the boardwalk. A tractor and auger was required because the buried ballast of the former railway had prevented a previous attempt by the Friends-of group to install posts to strengthen the dam using hand tools. On the downward side it was possible to secure the posts into the ground with concrete, while the posts within the pond (the boardwalk extends over the edge of the dam by approx 20cm) were placed into augured holes and rammed downwards until they were firm. In this way it was not necessary to drain the pond, or to lay concrete within it, both of which would have been harmful to the wildlife.

An oak rail was screwed to the outer edges of the lines of oak posts and the boardwalk sections were fitted over these and secured to them. The resulting structure is without movement and constructed of the most durable materials. In strengthening the dam, provision has been made in due course to raise the level of the water, which is currently about 15cm below the level of the boardwalk, by about 7.5cm. This simple procedure will be undertaken during the summer when the flow of water is reduced and it can be stopped for sufficient time for fast-curing cement to harden. This will increase the area of water and make it more accessible, more especially for children. Two, simple oak benches have been ordered from a local craftsman and will be installed by the Friends-of group in due course.

Three small bridges were constructed, two crossing the stream (which splits into two creating a small island) onto the new island and off again just below the dam, and a third where the path crosses water issuing from a spring. The bridges are of the same construction type and are sufficiently wide to take a pushchair/buggy.

Feedback from people who have visited PBNR since the works were completed and who have been met on-site, and those many people who have commented on the PBNR facebook page, has been unanimously positive and most encouraging; it has been gratifying for Friends-of group members to see the numbers of families with young children who are using the Nature Reserve now that access has improved. One child is reported to have said to her parents: “It’s so nice, why do we not come here more often?”

These various access arrangements provide a destination and access to nature for people of all ages. It is frequently remarked upon by local people who have lived in the area often for many years and have just “found” the place2 that PBNR is a strangely peaceful and most agreeable spot to find within the town. Where before the dam was an unsatisfactory, ad hoc collection of earth and boards3 there now is the chance for children to sit or lie safely and in comfort on the boardwalk and pond-dip and watch the pondlife, with benches for adults to rest while they do. It has become a desirable destination which will attract people of all ages for quiet recreation.

The path above (east of) Pilley Bridge, across the meadow, has been laid with bricks to provide a mud-free path 1m wide across a stretch of ground which had previously been passable in winter only by determined walkers in Wellington boots. The bricks were laid as a temporary measure in early winter to provide access through the winter using mostly low grade bricks (stocks) which are liable to corrosion by frosts. Plans are being made to up-grade the path during 2015 and purchase of engineering bricks to substitute for the stocks will soon be made. This will include adding drainage and a bed of sharp sand; it is anticipated that the outcome will be an all-weather path which will have an indefinite lifespan.

The stream now flows out of the pond down a newly-constructed spillway which has not been covered by the boardwalk; it remains a place for children to experiment with hydraulics and further to experience wild things. The boardwalk return (on the south side of the pond) provides access to both the side of the pond and to the marshland upstream which previously had been inaccessible. The marshland is a significant habitat in itself and it is hoped to be able to install an information board regarding the wildlife values of it and the ponds.

Works have been started, with the agreement of Cheltenham Borough Council rangers, to increase light levels to the pond and surrounding area by coppicing of the undergrowth, principally Hazel and Goat Willow. This should increase wildlife within and around the pond and provide further opportunities for recreation and study. While the Saturday work party was doing the work4 an early butterfly visited a newly-created patch of sunlight over the pond that had not been there the previous day.

Works not yet completed but which are within the funding package, apart from up-grading of the path across the meadow, are improvements to the section of path from the meadow to the ponds. This section remains unimproved because the contractors needed to drive their vehicles over it repeatedly and it would have been damaged in the process. The plan is to use the stock bricks which will become available when engineering bricks are substituted for them, to create a good all-weather path which will then be topped with gravel.

1 Free of charge.
2 It is remarkable how many people are met by members of the Friends-of group who say this.
3 Create a few years ago, most commendably, by the Cheltenham Borough Council rangers in haste to re-locate stranded amphibians.
4 The Friends-of group has a once-monthly work party in a Saturday morning which is well supported by up to 15 people.