Wonder how Bonaly Reservoir came to be? Let me tell you a story about this essential water source nestled in the Pentland Hills.
Bonaly Reservoir wasn’t always here. The story begins with a need. Edinburgh thirsted for fresh water in the 1800s. The Edinburgh Water Company sought a solution. They found it here on the north-west slope of Capelaw Hill.
The idea behind Bonaly Reservoir was twofold. It would provide drinking water and maintain water flow in local streams. The location was ideal but challenging. At 340 meters above sea level, the natural water catchment area was surprisingly small.
So, engineers devised a clever plan. They carved catch-drains into the hillside. These drains diverted rainwater and spring water into the reservoir. The present Bonaly Reservoir was not the first attempt here.
Before the reservoir, there were Bonaly Pools. In 1853, the Dean Burn was dammed with a stone-faced earthwork. This dam transformed Bonaly Pools into the Bonaly Reservoir we see today. It could hold 218 million liters. At its deepest, it reaches 7.5 meters. The remains of an older dam lie to the north.
Even before the reservoir, this site was a water source. Since 1761, Bonaly Pools supplied Edinburgh with water via a wooden pipeline to Swanston. Later, iron pipes replaced the wood ones at the end of the 1700s. This old pipeline was found during a survey in 2005.
Interestingly, Bonaly Reservoir is different from other Pentland reservoirs. Scottish Water does not manage it. It is managed by the City of Edinburgh Council.
Today, there are plans to manage water levels to help wildlife thrive here. Bonaly Reservoir stands as a testament to ingenuity. It reminds us of Edinburgh’s history and the vital role of water management. As you gaze upon this serene body of water, remember its journey from humble pools to a vital part of Edinburgh’s infrastructure. Bonaly Reservoir continues to quietly serve the community.