The Brockloch Burn is a small tributary of the Chapelton Burn in the River Doon Catchment. It has been the focus of some extensive but necessary alteration in recent years to accommodate the new Maybole bypass. At the north end of the bypass, the roundabout that was built meant the burn had to be moved while works were underway and moved back into a purpose built channel where it flows today.
During the monitoring of the fish populations ahead of work commencing, we discovered a single salmon fry upstream of the old railway bridge at Smithston in 2012. This was both surprising and encouraging as the burn suffered heavily from diffuse pollution with large silt deposits rendering the habitat less than good for spawning purposes. We were also rather surprised by the incredibly good eel numbers we found at the site. Since then, we’ve recorded salmon parr each time we surveyed and one 2+ years old fish in late summer. This is another unusual feature as most of the Doon salmon leave either as S1 or S2 smolts in Spring. This could just be an anomaly but we will age any future salmon from this area to better understand this population.
There are a few problems developing within the bypass area that we intend to raise with SEPA but overall, the new channel is ok, has improved over the last year and may improve further as it continues to naturalise
With the bypass completed and the team encouraged by our findings, we decided to address some of the other problems that limited production just downstream. The main issues were livestock related with cattle access leading to silt and nutrient inputs that were destroying what was otherwise potentially, good fish habitat and reducing water quality (see our earlier post ‘Silt and other issues affecting productivity’ from October 2018 on this web site).The following section of this report illustrates progress made by tackling the main land use issues.
2018 – Severe livestock poaching that led to impacted fish habitat
We had asked SEPA to intervene at least as early as 2018 when the above image was taken but with no real progress made to resolve the issues, we approached the landowner in 2022 who agreed to our proposals subject to us providing suitable watering points for his livestock. A mains supply was preferential but after investigating the cost of this, we had to rule this out in favour of a gravity fed system which we took from the burn some 400 m upstream. This was considered a rather inadequate solution and the landowner wanted a back up plan and gates for access should all else fail. Faced with these challenges we overcame the difficulties of syphoning water over such long distances (the hydrodynamics of syphoning water through pipes can be quite a challenge). We had a head height of around 5m over a distance of 400m so it was obviously possible but not as easy as we first imagined. Eventually we succeeded and ended up with a flow rate of around 1L/min or nearly 1500L/day which was adequate for the cattle’s needs. We then designed a solar powered back up system to kick in automatically should the gravity feed fail for any reason. These can deliver up to 20L/minute, again more than adequate for the needs.
With a grant from the Wild Salmonid Support Fund and a contribution from the River Doon DSFB, we erected fencing in late 2023. Some 400+m of new fencing and another 200m of old fence were erected and repaired to effectively exclude livestock from the burn. Gates were provided as requested and the gravity watering system installed. In spring2024 , we pushed on to install the back up solar powered automatic watering systems before the cattle went onto the pasture. Of course the further back up of gates that could be opened to allow cattle to drink from the burner also installed but that is exactly why we felt the need to intervene in the first place and something we wish to avoid at all cost, but at least they are there for eace of mind.
At we installed the gravity supply and face numerous difficulties, a few doubts crept in with some staff becoming rather doubtful that the syphon system would ever work but we persevered and succeeded. It is not just as simple as syphoning a bucket of water with a hosepipe as most of us will have done at some time. Leaves and debris presented challenges as they could quickly block the intake. Some creative thinking led to a very good solution that has stood the test of time. Undulations within the pipe also cause problems and there’s a risk that a vacuum forms due to the way water behaves within pipes over long runs. Problem solving is all part of the job and we worked things out by trial and error and now have a system that has run for months without any hiccups. This supply provides around 1,500L per day rain or shine, freeze or thaw.
The gravity fed system first fills one large 1000L tank which then overflows via a pipe to the trough on the opposite bank. In turn this second trough overflows back to the burn via another pipe. Both water troughs have automatic solar systems that come on if required with individual solar panels, charge controllers, batteries and pumps should the gravity system fail. Again faced with unique constraints, rather than following the easier and established routes of buying rather over-priced solar watering systems off the shelf, we set about custom building 2 systems for the job in hand and managed considerable savings over manufactured options. In future we can help landowners with similar systems and pass on savings too!
Since the fencing went up, the livestock have been excluded from the burn and away from the margins with great effect. Trees were planted to help stabilise erosion and ensure many years of shade will be provided once the existing trees have died off. Of course seedlings may now naturally genrminate and survive without the threat of the grazing cattle destroying them so in time this should become a varied and functional riparian woodland of value, bring benefits for not just fish and fish habitat but other riparian species too. Improving biodiversity can only benefit everyone and everything.
Rapidly improving habitat since the fences went up. . Bare soil has been replaced with many species of plants. This will benefit many species including fish and fish habitat.
More or less the same location as in the previous photo but this image was taken in 2018. The difference is clear for everyone to see.
The most striking change we have observed other than the incredible explosion of bankside vegetation is a massive reduction in silt on the bed of the burn. The gravel substrates are clearing with every spate and as silt inputs are reduced we expect this to continue. We should see the burn narrowing as marginal vegetation encroaches on the watercourse due to the lack of grazing pressure. As it does, the burn will steadily increase in energy where it becomes constricted, scouring the bed and moving gravels where once they were deposited along with silt. This is likely to increase the range depths within the stretch which typically was shallow and over-wide.Some banks may become undercut offering cover and shelter to fish. Cobbles and boulders are emerging already and they too offer cover and improved flow diversity throughout the reach. Over-wide and low energy burn habitat is often caused by livestock access as it was in this case.
The bed of the burn was covered with a thick layer of fine silt and sand back in 2018.
Looking at the bed of the burn from the same bridge as in the previous image. Where there was just silt, we now have clearing gravels. The banks have revegetated since the cattle were excluded. This is exactly the sort of improvement we expected to see.
Given time, we expect fish numbers will increase and hopefully salmon and trout spawning will take place within the project area. We will monitor fish populations and report back on our web sites with any updates. We will also keep an eye on the habitat downstream on the Chapelton Burn as it too is impacted by silt deposits. Perhaps this will improve as a result of this work too.
Any landowners wishing our assistance with livestock watering solutions please don’t hesitate to ask. We are always willing to help where we can and we may even be able to secure grant funding to assist for the right locations.Similarly we are able to advise on beneficial riparian tree planting and sustainable river management approaches. Just call us and ask if you have questions.
