More than 100 tonnes of concrete is to be poured into Chasewater Reservoir to help support the 200-year-old dam.
The concrete will help control the flow of water when the reservoir is full. Repairs to the reservoir’s drawdown culvert (or plughole), have also been carried out.
County councillor Mark Winnington said: “This is the last major milestone in what has been a hugely successful and high profile project to restore one of the most popular country parks in the Midlands to its former glory.
“The county council has carried out vital safety improvements to the overflow to safeguard nearby residents in the event of severe flooding, which will enable us to monitor the condition of the dam much more closely in the future.
“The drawdown culvert – the equivalent of the plughole in a bath – was located and inspected for the first time in over 200 years. Vital improvements have now been made and the project is expected to be complete in the spring.”
Water levels have begun to rise again after the plug was replaced last October. It is expected to be refilled fully by spring 2013.