Overview
Vartry Reservoir lies in the heart of the Wicklow Mountains, just outside the village of Roundwood, about 50 km south of Dublin. Operated by Irish Water, the scheme supplies drinking water to the capital via a network of pipes that end at an open service reservoir in Stillorgan. The complex consists of two linked bodies of water: the lower reservoir, completed in 1863, holds 11.3 billion litres and reaches a maximum depth of 18.3 m; the upper reservoir, added in 1923, stores a further 5.6 billion litres with a depth of 13.4 m. The dam and embankments are visible from the R764 and R755 roads that skirt the site.
History
The Vartry water‑works were born from a public‑health crisis in mid‑19th‑century Dublin. In 1861 Parliament passed the Dublin Waterworks Act, authorising the damming of the Vartry River to create a clean water supply for the city, replacing the polluted canal water that had previously been used. The Dublin Water Works Committee, chaired by Dr John Gray, oversaw construction of the lower reservoir, which opened on 30 June 1863. The new supply dramatically reduced cholera and typhus outbreaks and marked the first reliable source of treated water for Dublin.
A second embankment upstream was finished in 1923, creating the upper reservoir and bringing the total capacity to 16.9 billion litres. The engineering works were considered a marvel of their time, featuring a spillway that channels water from the upper to the lower lake before it is drawn off to filter beds below the R764. The reservoir even makes a literary cameo in James Joyce’s Ulysses (chapter 17).
What to See & Do
Vartry Reservoir is a hub for walkers of all ages. Three officially way‑marked trails loop around the lakes, each offering a different perspective on the water, the surrounding forest and the distant peaks of the Sugar Loaf and Djouce mountains.
| Trail | Distance | Difficulty | Way‑marker colour | Approx. time | Start point |
|---|---|---|---|---|---|
| Lower Vartry Trail | 7.2 km | Easy | Blue | 2 h | Roundwood village T‑junction (R755/R765) |
| Upper Vartry Trail | 6.4 km | Easy | Green | 1.5 h | Knockraheen entrance, east side of the upper reservoir |
| Woodland Trail | 3 km | Easy | Pink | 45 min | Knockraheen entrance |
Lower Vartry Trail follows a traffic‑free loop around the lower lake, skirting the water’s edge on well‑maintained paths. Walkers can spot a hollowed‑out Ballaun stone near the shore – a relic likely moved from a monastic site – and, when water levels are low, the remains of the original bridge that once crossed the Vartry River.
Upper Vartry Trail climbs gently around the upper reservoir, rewarding hikers with sweeping views of the Sugar Loaf and Djouce ranges. The route includes a few steeper sections, but the gradient is modest and the trail is fully way‑marked in green.
Woodland Trail is a short, family‑friendly stroll through a stand of century‑old Scots Pines that separate the two reservoirs. Birdwatchers often hear Great Crested Grebes calling from their floating nests, and the shaded cutting offers a cool respite on sunny days.
Ecology & Birdwatching
The Vartry catchment is recognised for its good water quality and diverse wildlife. The reservoir’s woodland edges support mature pine trees, providing habitat for a range of birds. Regular visitors report seeing:
- Great Crested Grebe
- Little Grebe
- Mute Swan
- Little Egret
- Grey Heron
- Black‑headed Gull
- Mallard
- Hooded Crow
- Grey Wagtail
The open water and surrounding reeds also attract wintering wildfowl and occasional raptors. Spring and early summer are the best times for birdwatching, when grebes are nesting and the pine woods are alive with songbirds.
Visitor Facilities
Vartry Reservoir is freely accessible year‑round; there are no formal opening hours or admission charges.
Parking – Two main car parks serve the trailheads:
- Upper Vartry Car Park – at the Knockraheen entrance (approx. 20‑car capacity, GPS 53.071746, ‑6.204767).
- Lower Vartry Car Park – near the start of the Lower Trail in Roundwood village. Both car parks are free and include basic facilities such as public toilets and signage.
Accessibility – The lower route is largely level and suitable for strollers and wheelchair users. All three trails are way‑marked and dog‑friendly.
Maps – Detailed trail maps are available from Sport Ireland:
Nearby Attractions
The reservoir is a springboard to other Wicklow highlights. The village of Roundwood, a two‑minute drive from the trailheads, hosts cafés such as the Sugar Mountain Café and the An Tohar House pub, perfect for a post‑walk bite.
A short drive also leads to the former Victor’s Way sculpture garden (now closed) and the spectacular Sally Gap drive, a circular route that showcases Lough Tay, Ballinastoe Woods, Djouce and Glenmacnass Waterfall.
For mountain‑bike enthusiasts, the nearby Ballinastoe MBT offers purpose‑built trails within the same forested landscape.
Practical Information
Vartry Reservoir is operated by Irish Water, but no visitor centre is on site. The surrounding landscape is managed by the Irish state and forms part of the Wicklow Mountains National Park’s broader network of walking routes.
Getting there – From Dublin, take the M50 to the N11, then follow signs for Bray and the R755 to Roundwood. The journey takes roughly one hour by car. Public transport options are limited; the nearest bus stop is in Roundwood village, and a taxi from Bray or Wicklow town is a convenient alternative.
Nearby amenities – Roundwood offers a range of cafés, pubs, shops and accommodation options, as well as public restrooms. The village is a pleasant place to rest, refuel and enjoy a traditional Irish pint before or after your walk.
Enjoy the blend of engineering heritage, tranquil water, and mountain scenery that makes Vartry Reservoir a unique stop on any Wicklow itinerary.