Low-Head Hydropower Facility Construction: Resource Requirements and Impact Sources
Potential impacts from low-head hydropower facility construction affect large areas of the site, but are temporary in nature.
Throughout facility construction, large areas of the site would be impacted by site preparation activities such as clearing; construction of access roads; preparation and use of material and equipment laydown areas; construction of the intake system, which could include a dam or weir; construction of canals, tunnels, and pipelines; construction of the powerhouse and installation of the turbine and generator; and construction of the electrical substation and transmission line. Concrete ingredients such as sand and aggregate may also need to be extracted and hauled to the site unless there is an appropriate on-site borrow area.
The following factors could affect whether an environmental impact could occur and whether it would be considered an adverse effect:
Acreage — The low-headhydropower facility site could encompass up to 2,000 acres. Land disturbance would not involve most of the site. Temporary disturbance would occur for laydown areas (10–20 acres) and ancillary facilities (e.g., 10–15 acres for concrete batch plant). Up to 20 acres would be flooded to create the head pond if a weir or dam is required. A canal or pipeline to convey the water from the intake to the powerhouse could be as long as 10,000 ft. Acreage for access roads would depend upon project location. The powerhouse is a small building, typically 30 ft by 50 ft.
Waste Generation — Wastes generated would include industrial wastes routinely associated with industrial facility construction activities such as waste oils, lubricants, and coolants from the on-site maintenance of construction vehicles and equipment, spent solvents, cleaning agents, paints, and small amounts of wastewater; and solid wastes such as containers, dunnage, and packaging materials.
Water Needs — Water would be required for fugitive dust control (depending on local conditions); making concrete; potable water for construction crews; and fire contingency supply.
Workforce — Size varies, but the typical workforce could require as many as 15 individuals. Specialty crews would be present on the site only long enough to complete their specialized tasks. The general construction crew would be of relatively constant and modest size throughout the construction phase. Typically, none of the workforce would reside on-site, but minimal support facilities might be required for weather contingencies.
Time and Materials — Construction of a low-head hydropower facility would occur over a period of 12–24 months.
Utility Requirements — Utility requirements would vary depending on location; use of on-site generators is probable.