Allt an Eoin Hydro Scheme, Scotland

Allt an Eoin is a 450kW high head scheme located in Glenmoriston, near Fort Augustus. Dulas was commissioned by Dulas Hydro Generation Ltd to deliver the scheme as a turnkey design and build contract. The scheme has two primary intakes and a secondary that feeds a low pressure pipeline delivering water upstream of a primary intake.
1.5 km of pressure pipeline of HPPE and ductile iron pass beneath one watercourse and bridge another.
The specification was developed with the client to deliver a scheme with a focus on maximising availability whilst minimising cost and environmental impact. This required extensive value engineering to determine the optimum pipeline-turbine combination, the construction requirements and control system specification. To deliver optimal
performance at minimum cost from the high head and low flow, a single-jet Pelton was selected. The pipework around the powerhouse required special consideration to provide adequate maintenance features and withstand 24 bar operating pressure.
The scheme is equipped with facilities for pigging, a full coverage gantry within the powerhouse, lifting davits at intakes, de-watering facilities and safe access provision for routine and occasional maintenance.
The scheme was delivered using an NEC3 Engineering & Construction Contract with Dulas acting as Principal Contractor as well as preparing the full civil, mechanical and electrical design packages.
We have worked with Dulas for many
years and would recommend them to
others considering a hydro scheme.