Threipmuir and Harlaw Reservoirs
Balerno, Edinburgh
Threipmuir and Harlaw sit in the Pentland Hills Regional Park south of Edinburgh, two reservoir loops joined by open hillside and quiet farm tracks. It is an unpretentious walk: wide paths, long sight lines, room to move. One of the most popular dog walks on the edge of the city for exactly those reasons.
The Scottish Outdoor Access Code applies, which means dogs can be off-lead under proper control for most of the circuit. Cattle graze the hillside sections at certain times of year. When they are present, keep your dog on a lead. The cattle here are large and can be assertive, and standing your ground calmly works better than moving quickly away.
The reservoirs are Scottish Water supply. Dogs cannot swim in them. Ticks are a consistent hazard across the Pentlands from spring through autumn. Check your dog carefully after every visit.
Bavelaw car park at the foot of the hills charges around two pounds. The Balerno Inn is the nearest dog-friendly option, about a mile from the car park.
Frequently asked questions
Can my dog swim in Threipmuir or Harlaw Reservoir?
No. Scottish Water owns and manages both reservoirs as drinking water supply. Swimming is not permitted for humans or dogs. Dogs should not be encouraged to enter the water. The reservoir banks are accessible but the water is cold, drops away sharply, and a dog that enters may struggle to get out. Keep dogs on a lead near the reservoir edges.
Are there ticks in the Pentland Hills?
Yes - the Pentlands are significant tick habitat. Sheep, deer, and dense vegetation create ideal conditions. Use a vet-approved tick prevention treatment before visiting. Check your dog immediately after the walk - between toes, around ears, under the collar. Peak season is April to October but ticks can be active in mild winters.
What livestock will I encounter and when are restrictions tightest?
Sheep and cattle both graze the hills adjacent to the reservoir paths. Sheep lambing typically runs March to May. During lambing, even a dog on a lead can stress a ewe enough to cause her to abandon a lamb. Pentland Hills Regional Park states explicitly that dogs have been shot in the park for worrying livestock. Keep your dog on a short lead whenever livestock are visible.
Who manages this area and what access rights apply?
The Pentland Hills Regional Park is managed by the City of Edinburgh Council in partnership with neighbouring authorities. The Scottish Outdoor Access Code applies. The reservoirs are owned by Scottish Water - access rights under the Land Reform (Scotland) Act 2003 allow you to walk the paths, but Scottish Water restrictions on the water itself still apply.
Plan this walk with live weather and dog-safe route info