One of the most important sites in the history of the Welsh language is being protected from the threat of flooding and heavy rainfall by harnessing the element that is putting it at risk.

The upland farmhouse Tŷ Mawr Wybrnant in Snowdonia, north Wales, is the birthplace of Bishop William Morgan, whose translation of the Bible in the 16th century was a key moment for the Welsh language.

An original copy of Morgan’s Bible is on display at the restored stone house, but both the building and the book have been put in jeopardy by flooding and heavy rainfall.

The National Trust, which manages the building near Betws-y-Coed, has now installed a pico (mini) hydropower scheme that will use a stream to run an improved heating system and keep humidity levels in check.

Tŷ Mawr Wybrnant, near Betws-y-Coed. Photograph: National Trust/Iolo Penri Photography

The stream burst its banks earlier this year, leading to the worst flood in living memory. One of the ground-floor rooms at Tŷ Mawr Wybrnant was inundated, and although the Morgan Bible is kept in a special cabinet on the first floor, the extra moisture put it, and other books, at risk.

Keith Jones, the National Trust’s climate change adviser, said: “That extra moisture meant we needed to use more heating to ensure the humidity levels didn’t get too high.

“Climate predictions indicate likely increases in the severity and frequency of rainfall in the area. This small-scale technology is allowing us to adapt to future changes more sustainably.”

The first Bible to be translated into Welsh is one of the most important books in Welsh history. Photograph: National Trust/Iolo Penri Photography

The charity worked with researchers from Bangor University in north Wales and Trinity College, Dublin, to develop the scheme.

Jones said a percentage of the stream’s flow would only be used once water levels reached a certain point.

“This means we are generating the electricity when we most need it, when there’s more moisture in the air after rainfall. The energy is consumed directly onsite, solely for the conservation of this priceless Bible collection.

“At Tŷ Mawr Wybrnant, water is actually helping us solve a problem it’s creating in the first place, so there’s some kind of poetic justice there. We’ll be exploring how this principle could be used where other collections may be similarly at risk.”

Tim Pye, the National Trust’s libraries curator, said: “The Bible at Tŷ Mawr Wybrnant is a hugely important part not only of the property’s story but of the history of the Welsh language.

“William Morgan’s translation of the Bible, primarily from Hebrew and Greek, helped standardise the Welsh language and is considered to be the single most significant step in ensuring the survival of that language today.”

Inside Tŷ Mawr Wybrnant. Photograph: National Trust/Iolo Penri Photography

Tŷ Mawr means “big house” in Welsh, and Wybrnant is thought to derive from “nant” (stream) and “gwiber” (snake), so “snaking stream”.

The building houses a small but significant collection of family Bibles, along with some in more than 100 languages that have been donated by visitors from around the world.

The trust restored the farmhouse to how it would have looked in Morgan’s time and opened it as a museum in 1988, on the 400th anniversary of the Bible translation being published.

Tŷ Mawr Wybrnant has closed for the winter but will reopen to visitors in the spring.