Last updated: April 2026 | Author: Angus Hughson, Big Ditch Dam Building Company
What is dam dead storage?
Dam dead storage is the volume of water which is below the level of the spillway or other outlet. In other words, the volume of water that cannot be released from a dam (unless the dam wall bursts). The capacity, volume or storage of a reservoir is usually divided into distinguishable areas.
Dead or inactive storage refers to water in a reservoir that cannot be drained by gravity through a dam’s outlet works, spillway or power plant intake and can only be pumped out. Most dams have multiple options for discharge. The lowest usually is a penstock. Lets say your lowest penstock opening is at 1770 feet above mean sea level. The lowest point of the riverbed upon which the dam is built is 1720′ msl. All the water from 1720′ to 1770′ msl is “dead storage” water because it can never be accessed.
It usually does not account for much on a percentage basis in the reservoir, but it must be accounted for in storage projections. -David Stevens, former Engineering Director
At the same, while doing these projections, it is important to make sure that all the regulations are taken into account to ensure the proper functioning of a dam.
Frequently Asked Questions
How much does it cost to dead storage and why does it matter for your dam??
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 dead storage and why does it matter for your dam??
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 dead storage and why does it matter for your dam? 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 dead storage and why does it matter for your dam??
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.