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Cardiff’s iconic reservoirs

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Nature In Cardiff

Lisvane & Llanishen Reservoirs forms a vital part of the green and blue infrastructure of Cardiff.

The mix of grassland, woodland, scrub and waterside habitats offers opportunities for all kinds of wildlife and nature. There are two Sites of Special Scientific Interest (SSSI) and much of the grassland and woodland outside of the SSSIs is designated as a Site of Importance for Nature Conservation (SINC).

Lisvane & Llanishen Reservoirs is one of four protected green corridors into the city, connecting the urban landscape with the ancient woodland to the north.

Sites Of Special Scientific Interest (SSSI)

Lisvane & Llanishen Reservoirs encompasses two statutory Sites of Special Scientific Interest (SSSI) and considered to be of national ecological value. Lisvane Reservoir SSSI is designated for its overwintering wildfowl and Llanishen and Lisvane Reservoir Embankments SSSI is of special interest for its diverse assemblage of grassland fungi including up to 25 species of waxcap.

Sites of Importance for Nature Conservation (SINC)

Llanishen Reservoir is designated because of its large population of common toads and presence of locally rare water plants. The stone pitching around the reservoir margin is known to support locally important populations of lichens, and several locally uncommon mosses.

The grassland and scrub around Llanishen Reservoir is designated mainly because of its populations of grass snakes and glow worms.

Also designated, the woodland to the south comprises marshy alder carr whilst those to the west are mostly oak, alder and birch, all supporting a rich array of wildlife.

Dogs At Lisvane & Llanishen Reservoirs

Dogs are permitted on the café balcony, car park and Grab & Go seating area only and are not permitted anywhere else on the site, including the paths.

We know that this will be disappointing news to many nearby residents who would like to walk their dogs at Lisvane & Llanishen Reservoirs but we have to take seriously any threat to its designation as a site of special scientific interest (SSSI) for the rare waxcap fungi.

Natural Resources Wales has advised that the risk from dogs to the fungi is too great. Waxcaps are very sensitive to changes in habitat such as fluctuations in soil moisture, temperature and nitrate levels which can reduce the production of fruiting bodies. In particular, sudden changes to nitrate levels on the site – from dog urine specifically – can have a detrimental effect on the fungi.

Please note that the restrictions are not applicable to assistance dogs.

Wildlife & Nature

The site is home to a variety of protected species including grass snake and the occasional otter. Bats use the site for feeding and there have been past records of roosting bats. Bat boxes have been placed around the site to encourage bats to use the woodlands for roosting.

Other notable species include common toad, common frog and palmate newt.

By introducing a wildlife haven and managing the grassland scrub, we are hoping to encourage the species to thrive again on the site. 

Wildlife & Nature Highlights


Explore our nature trails in the semi-ancient and more recently established woodland on site. Find out about our education zone and wildlife haven…


Birds & Birdwatching

The mix of woodland, grassland and waterside habitats makes this an area rich in birdlife. Discover which birds make Lisvane & Llanishen Reservoirs their home.



The embankments of Lisvane and Llanishen Reservoir are of special interest for their significant populations of grassland fungi, particularly the rare waxcap…


Plants & Insects

Wild-flowers flourish at Lisvane & Llanishen Reservoirs, as they did in the hay meadows of earlier times, and they attract a variety of insects, particularly butterflies.


Take Care

In order to help us protect the diversity of wildlife at Lisvane & Llanishen Reservoirs, please take care when you walk around the site.

Please use signposted trails only and keep off the grass at all times.

Please take notice of our seasonal path closures.