Last updated: April 2026 | Author: Angus Hughson, Big Ditch Dam Building Company
How do hydro-electric dams still generate power if the rivers freeze?
When it comes to dam maintenance, a lot of owners are curious how their dam will operate in winter. And here is an answer:
Rivers only freeze on the surface, below the surface they still flow, unless they are really shallow. Ask any fish.
Intakes for the dams are underwater, not at the surface, so hydroelectric dams still work quite well.
The most common hydroelectric situation involves a deep reservoir created upstream of a dam, and these do not freeze due to the water depth. (Bear in mind, that even on a still lake, the ice depth rarely exceeds one metre.) Another type, called “run of the river” which are commonly smaller, can be subject to freezing, depending on the river depth and flow rate.
The “run of the river’ type are used in situations in which the surrounding area is to be preserved. Frequently, these exist in urban situations which had a seasonally operated gristmill or sawmill that was evolved to become a hydroelectric generator. It would be unfeasible to tear out most of the town around that to create a reservoir.
-Loring Chien, Engineer
Frequently Asked Questions
How much does it cost to winter performance of hydroelectric dams: what changes when it’s cold?
Costs vary significantly depending on dam size, soil conditions, location, and access. Big Ditch provides fixed-price quotes after a site inspection. Contact our team for an accurate estimate tailored to your property.
Do I need council approval for winter performance of hydroelectric dams: what changes when it’s cold?
Requirements vary by state and dam size. In NSW, QLD, and VIC, dams above certain storage volumes require approval. Big Ditch handles all regulatory compliance as part of our service — contact us to discuss your specific situation.
How long does winter performance of hydroelectric dams: what changes when it’s cold take?
Timeline depends on dam size, soil type, weather, and site access. Most farm dam projects take between 3–14 days of machine time. Big Ditch will give you a realistic schedule during your site inspection.
Can Big Ditch help with winter performance of hydroelectric dams: what changes when it’s cold?
Yes — Big Ditch specialises in earth dam construction, repair, and maintenance across Queensland, NSW, and Victoria. We offer fixed-price quotes, 10-year guarantees, and over 30 years of experience. Call us or book a site inspection to get started.