Hydrological and Flooding Assessment, Tornagrain

A comprehensive hydrological and flooding assessment for a new mixed-use development at Tornagrain, Highland. The project involves the redevelopment of a former steading and water mill site, with detailed flood risk management and environmental restoration. A planning condition required the retention of the historical steading building, which was at risk of flooding from the nearby watercourse.

The project features detailed 1D and 2D hydraulic modelling to provide comprehensive information on flood extents, routes and mechanisms. The engineering solution includes a two-stage channel design with a step-pool system to slow flow velocity, reduce erosion and prevent catastrophic bank failure. The former mill pond area has been designed as a flood storage area, creating valuable wetland habitat while serving as a landscape amenity feature.

The primary challenge was protecting the historical steading building from flood risk while enabling productive use of the structure. This required sophisticated hydraulic modelling and the development of innovative flood mitigation schemes that work with the natural landscape. Additional challenges included developing a Construction Environmental Management Plan, Quarry Management Plan, and advice on re-use of surplus soils.

The flood mitigation scheme successfully reduces flood risk to the historical steading while providing multiple environmental benefits. The naturalised channel form with step-pool systems enhances ecological value, the restored mill pond area creates valuable wetland habitat for wildlife, and the overall design provides an attractive landscape amenity for residents and users. The project demonstrates how heritage preservation can be successfully integrated with modern flood risk management and environmental enhancement.