This February saw some of the heaviest rainfall on record nationally, and we’ve seen plenty of examples locally of how water finds its way down through the River Holme catchment in apparently new and previously unnoticed ways: down hillsides and roads, through over-full dikes and streams, spilling over into gardens and farmland, collecting in places where drainage is poor and creating dangerous ‘lakes’ on busy highways.
We have had our share of serious floods in the Holme Valley of course: The Holme burst its banks in 1738 and 1777; the famous 1852 flood resulting in the loss of 81 lives when Bilberry dam failed; the 1944 flood following a cloudburst which again saw Bilberry dam breached resulting in the loss of three lives; and the flash-flooding of 2002, caused by following a heavy rainstorm. The Holme is considered by the Environment Agency to be ‘heavily modified’ by human activity’, by channel works and industrial activities and other human activities.
In more normal times, the tributaries that feed into the River Holme are many. Some dry to a trickle in hot summer weather, something hard to imagine during such a wet winter.
The Holme Catchment is just over 96.5 square kilometres. The main tributaries are the River Ribble, which drains Holme Styes reservoir and connects with the Holme in Holmfirth; New Mill Dike, connecting at Mytholmbridge; Hall Dike and Magg Brook, which flow through Meltham then Honley respectively; and Digley Brook which flows from Digley Reservoir to the Holme at Holmbridge.
The Digley Brook is perhaps one of the most significant, because of its association with the floods mentioned above. The source of the Holme is some 28 kilometres upstream from its confluence with the River Colne in Huddersfield. From the source at Dean Head Hill/Dean Head Moss, Dean Clough and Marsden Clough flow over Wessenden Head Moor into Bilberry Reservoir, on through Digley Reservoir, then through Digley Brook to the Holme at Holmbridge. Bilberry Reservoir holds around 67 million gallons (around 254 thousand cubic metres) of water and drains into Digley Reservoir, which at full capacity holds 600 million gallons (2.2 million cubic metres). The chemical water quality of the Holme and its tributaries is classified as ‘Good’ by the Environment Agency.
The geology of the area through which Digley Dike flows is Upper Carboniferous Namurian (Millstone Grit) rock. There are three quarries at Digley Reservoir: Digley Road Turnaround, Bingley Quarry (in use from 1881 – 1894); and Alison Quarry. The quarries were exploited in the 1940s for building Digley Dam.
The vegetation of the area through which Digley Brook flows is dominated in the upper reaches by heather and cottongrass. Bilberry grows further down (naming Bilberry Reservoir was a stroke of genius) around Digley reservoir and as the brook descends below the reservoir the area is wooded with oak and birch. The River Holme has problems with invasive species such as Himalayan Balsam and Japanese Knotweed. River Holme Connections have been active in regular ‘Balsam Bashing’ and the treatment of Japanese Knotweed (which must be done by licensed operatives). Keeping the tributaries free also of these is vitally important.
We are fortunate to have access to such beautiful waterways in our locality. Digley Reservoir is a very popular site for family walks, sadly curtailed in more recent weeks due the restrictions of the Covid-19 virus pandemic.
David Allsopp, volunteer 15 April 2020