Description. About Us. Great River Hydro (GRH) is New England’s largest producer of conventional hydropower. We own and operate 13 generating stations and 3 storage-only reservoirs on the Connecticut and Deerfield Rivers. Today, our unique capabilities and operational flexibility play a vital role in our region’s transition to a low carbon, reliable and secure energy future. At GRH, our most important asset is our people. The GRH team includes ov...