Winooski No. 8, also known as the Montpelier No. 4 Dam, is a private hydroelectric structure located on the Winooski River in Montpelier, Vermont. Completed in 1985, this concrete gravity dam stands at a height of 30.8 feet and has a length of 227 feet. With a storage capacity of 46 acre-feet, the dam serves the primary purpose of generating hydroelectric power.

Managed by the Federal Energy Regulatory Commission, Winooski No. 8 has a low hazard potential and a very high risk assessment rating of 1. The dam features a controlled spillway with a width of 176 feet and is equipped with one slide (sluice gate) outlet gate. Despite not being state regulated, the dam is under federal jurisdiction and is subject to inspections by the Federal Energy Regulatory Commission.

Water resource and climate enthusiasts will appreciate the strategic location of Winooski No. 8, as it plays a crucial role in harnessing the energy potential of the Winooski River while maintaining a balance between environmental conservation and power generation. The dam's operational efficiency and risk management measures make it a key asset in Vermont's renewable energy infrastructure, contributing to the sustainable development of the region.