Hospitality · Ras Al Khaimah, UAE · 2025

A valley that keeps its water

A resort at the seasonal lake behind the Wadi Ghalilah Dam, in a valley of the Hajar mountains. The design started with the water, because here everything else follows from it.

The brief

The site is a seasonal lake behind a dam in the mountains, some eighteen kilometres from Ras Al Khaimah city. The rains are short and heavy; the valley fills in hours, then recedes for months.

The seasons set the second frame. November to March runs 18–28 °C and dry. June to September, 38–45 °C at high humidity. In the cool months the place is compelling on its own; in the hot ones something other than shade is needed.

The question was not what to build around the lake, but how long the lake stays.

The answer

The lake lives on the hotel's own water. Greywater from showers, basins and laundry passes through sedimentation, a reed-root biofilter and UV disinfection, then returns to the lake. The lake is at once the final polishing stage of the system and its reserve.

The reed stands between the water and the shore. It shades the surface, calms the air moving across it, and takes up what the greywater brings. Where there is reed there are birds: within a few years the reed edge becomes the only permanent wetland in the valley.

Greywater does not fill the lake. It lengthens the time between two rains.

What it took

The reed continues onto the buildings. The arish — the traditional Emirati structure of dry palm leaves, trunks and fibre rope — was reported by the Architectural Review to run twenty-three degrees cooler inside than the neighbouring dunes. It does not insulate; it breathes. The one-metre gaps between units shade each other and let strong wind pass.

That became the facade: an outer reed layer, a cavity behind it, working by stack effect. Wall structures from site sand, 3D-printed — a process with several built examples in Dubai. Reed as a facade material and reed-bed water treatment both rest on published work: the former in the Delft University of Technology repository, the latter from Khalifa University.

Solar surplus can be buffered by gravitational storage: a pump raises water to an upper reservoir by day, a micro-turbine releases it at night. The valley provides the head; the detailed study is still to come.

Planting starts with the design

Reed can go in during the first month, long before construction. Landscape grows slowly and buildings quickly. If they start together, everything is new on opening day.

Month 0reed planting begins Month 6permitting under way · reed establishing Month 12construction starts · reed in its second year Month 18greywater loop connected Month 24opening — with an established reed edge

One handover has to be planned for in advance. There is greywater only once there are guests. Until then the reed grows on construction water and early rainfall; greywater takes over on opening day.

The season

In the cool months the valley supplies the programme. The Stairway to Heaven, Wadi Naqab and Jebel Jais Balcony Walk routes, 15–25 km e-bike circuits, birdwatching along the reed edge, night astronomy from the hillside plateau.

For the shoulder season — April, May, October — a desert plein-air school. A painting and photography residency on the model of the Nagybánya and Zebegény artists' colonies. The least-used resource in a desert is its light and its silence; a school can be built on those, not only a photograph.

Summer stays quiet. Small, well-shaded, naturally ventilated buildings make a July afternoon bearable — but the valley rests then, and the calendar treats it that way.

Data

Location: Wadi Ghalilah Dam, Ras Al Khaimah, United Arab Emirates
Year: 2025
Type: Resort at a seasonal lake
Areas studied: Greywater reuse · reed as facade · double-skin ventilation · 3D printing from site sand · gravitational energy storage · planting programme
Our role: Concept design, feasibility study, visualisation
In collaboration with: SVA Architects & Associates
Status: Concept design

View from the crest of the dam wall: rock-faced slope, the reed-edged lake behind it, curved sand-coloured resort units and a pool to the right — The dam from the valley: the rock-faced dam wall, the seasonal lake behind it, the Hajar escarpment.

The valley from above: sand-coloured units scattered around the lake, footpaths between them, the valley floor left unbuilt — The valley from above — building follows the shoreline; the valley floor is left alone.

The lake at dusk, mirror-still; terraced units along the left shore, reed at the water's edge and a jetty with a tented pavilion — The units terrace along the shoreline. The middle of the valley stays open.

Arrival space: curved concrete surfaces with a large opening to the landscape, a stone path across the floor, tall grass beds around it and a monolithic reception desk to the right — Arrival does not open with a lobby but with reed: the material of the shore comes inside.

Interior with a long glass wall showing underwater planting and fish behind it; a stone bench in front with two guests seated — A section through the reed-bed filter, behind glass — the treatment is visible from the guest side.

Room interior with a reed-clad wall behind the bed, timber beam ceiling and a large window onto the landscape — The facade material continues indoors: a reed panel behind the bed, palm-trunk beams above.

Room with bathing area: a freestanding stone tub with a planted reed bed separating it from the sleeping area, warm concealed lighting — Between tub and bed there is no partition but a reed bed. The room follows the same rule: where there is water, there is reed.

A plunge pool among rocks at night, lit faintly at ground level, under a star-filled sky — A plunge pool among the rocks. Lighting stays at ground level so the sky remains.

A pool built into a hillside plateau at night with bathers in the water, the Milky Way overhead and a mountain silhouette beyond — Night Sky Pool — body-temperature water on a hillside plateau, with no artificial light.

Visualisations of an unbuilt scheme, not photographs · post-production includes AI-based upscaling and retouching

Ren Design is an interior architecture practice based in Budapest, working across Europe and the Gulf. On this project it produced the concept design, the feasibility study and the visualisations, in collaboration with SVA Architects & Associates.