Watermill Broad was originally a square kilometre of relatively unproductive farmland, the seeds of the current reserve being sown when gravel was discovered underneath it. A condition of the extraction licence was that the site was rewilded once the commercial operations had ceased, and in the mid-1990s the pits were flooded, creating the current chain of ponds and lakes, with ecologists advising on the landscaping at the entrance to maximise ecological diversity. At this point, Angela Knapp purchased the site from then-owner Chris Brown and placed it in trust, ensuring that it remained as a private nature reserve. The Northwest half of the site has long been designated as a County Wildlife Site and the boundary was extended to cover the entire site in April 2024.
The water quality at Cranwich is extremely high, as indicated by the number of stonewort species found on site and the abundance and diversity of the aquatic invertebrate fauna, including water scorpions, water stick insects and Great Silver Diving Beetles. The Common Toad population is one of the biggest in the country, in no small part thanks to the dedicated work of the Cranwich toad patrol, and this supports a significant Grass Snake population that was the focus of a recent British Trust for Ornithology (BTO) PhD study. The most common breeding bird on site is the Reed Warbler, which also benefits from the super-abundance of aquatic insects, and the c. 120 nesting pairs have been the subject of a targeted monitoring project since 2010, which has supported two BTO PhD students to date. The Reed Warbler nests are appreciated by the local Cuckoos, as well as local researchers, and even attracted Sir David Attenborough himself, featuring in his Natural Curiosities series. The size of the breeding Reed Bunting population is also significant, as is that of Marsh Tit in the wet woodland surrounding the pits, and Watermill attracts good numbers of wildfowl and the odd Bittern during the winter months, with Great Egret being an increasingly common visitor. Bird populations are monitored routinely through ringing, nest recording and the Wetland Bird Survey counts, and other taxa are covered by regular visits from country recorders and recording groups, building a very comprehensive picture of the biodiversity on site.
Dave Leech, April 2024
Donations
Watermill Broad is a charity, number 1098299, and is financed by grants and donations. All donations, however small, are very welcome. Donations do not qualify for Gift Aid.
To donate, you can make an electronic payment to the following account:
Account Name: Watermill Broad Nature Reserve
Sort Code: 20-28-20
Account Number: 7025 2689