January Blog 1/12
There are 12 special qualities you need to understand and experience on the Mendip Hills. Each month in 2019 we’ll be introducing you to one of these special qualities. Individually they are important, together they are what makes Mendip an Area of Outstanding Natural Beauty.
Turn on the tap thanks to the Mendip Hills #mendipwater
Everyday thousands of people experience the effect of the Mendip Hills in their own home. If you live near Mendip or around Bristol chances are when you turn on the tap you’ll be drinking water that has landed on the hills, percolated through the limestone and been caught in the local reservoirs.
The entire Mendip Hills lies over an important Carboniferous Limestone aquifer, an underground layer of water-bearing permeable rock, which makes a major contribution to public water supply for Bristol, and the surrounding area via Cheddar, Blagdon, and Chew Valley reservoirs. The Mendip aquifer also supplies the hot springs in Bath.
The three reservoirs, Chew, Blagdon and Cheddar, supply water to 1.1 million people and businesses in the Bristol Water area. Both Chew Valley Lake and Blagdon Lake are now internationally important for wildlife. Chew and Blagdon are designated as Drinking Water Protected Areas with the catchments that drain to the lakes also identified as Safeguard Zones. The Environment Agency, Bristol Water, Natural England and other partners are developing Drinking Water Protected Area Safeguard Zone action plans to address the sources of nutrients in the lakes.
A large part of the AONB is within a Groundwater Source Protection Zone due to its contribution to the public water supply. Ground water quality is generally good overall, although there is a need to reduce sources of diffuse agricultural pollution in to the groundwater and water courses and also reduce run-off and soil erosion into watercourses.
There is generally a low risk of flooding within the hills as rivers tend to flow underground in a limestone landscape, creating the stunning caves. However flooding has been experienced in the Chew Valley and Cheddar areas where underground streams and rivers emerge. If you look at a map you can see where these water courses emerge from underground as the villages are built on these ‘springlines’, look for the A371 to the south and A368 to the north.
The Mendip Hills get a lot of rain (1135mm a year on average) and this tough weather is all part of the character, but the rain and the hills provide an important ‘ecosystem service’ to the community, that’s why it’s one of the Special Qualities.