In January 2022, we began our restoration work at Cors y Sarnau. The first phase of restoration involved removing scrub from the peatland areas, which needed to be completed before the start of nesting bird season in March. Our contractors and volunteers managed to clear a total of five hectares of scrub from the Coed Tŷ Uchaf restoration area, and a further one hectare from open fen and mire habitats on the Cors y Sarnu SSSI.
With the scrub cleared we were able to get our first good look at the restoration area at Coed Tŷ Uchaf and, with the help of a drone survey and hydrological experts, start to understand the drainage problems on this peatland. Our original simple model of the site – sloping down towards the north, with drains running south-north and southeast-northwest into a major drainage channel – turned out to be incorrect.
Instead, the peatland forms a gentle dome shedding water to both the north and south. And, to our surprise, the drainage ditches don’t connect directly into the main drainage channel and much of the water flow is directed around the perimeter of the area. The hydrology report also noted that there was a significant height difference – up to two metres – between the edge of the peatland and the base of the adjacent drainage channel.
With this information, we are now planning the next phase of restoration, which will aim to improve the water balance in Coed Tŷ Uchaf. This will focus on two areas: reducing flow rates and increasing the water height in the main drainage channel, in order to reduce hydrostatic pressure from the peatland; and installing bunds and dams to reduce water flow into the perimeter drains. Groundworks for this restoration phase are due to commence in September 2022.
https://www.northwaleswildlifetrust.org.uk/care-peat-cors-y-sarnau