The Environment Agency is hoping to be granted planning permission this week for the latest project to help prevent flooding in parts of Crawley.
The Upper Mole Flood Alleviation Scheme was developed by the Environment Agency after the floods in 2000.
So far, a flood storage reservoir at Tilgate Park has been completed and a reservoir at Worth Farm near the Maidenbower junction of the M23 is near completion.
Plans to replace the dam at Clay’s Lake near Pease Pottage with a larger one, were first submitted to Mid Sussex District Council in 2011 but have been subject to delays.
They were last refused on the grounds that there would have been more lorry movements than were necessary on the small, rural Parish Lane.
The Environment Agency is now awaiting the council’s decision for updated plans to improve the dam, which will increase the capacity of the lake from 10,000 cubic metres to nearly 400,000 cubic metres.
There is currently nothing stopping water flowing freely into the Stanford Brook, which runs downstream to Maidenbower into the Gatwick Stream in Three Bridges and Gatwick.
In the latest plans water will only be able to pass through a small hole in the bank.
Crawley Borough Council members Nigel Boxall (Con, Tilgate) and Ken Trussell (Con, Maidenbower) were viewing the plans at an exhibition on Thursday (January 23).
Cllr Trussell, also cabinet member for the environment, said: “We are fully aware of the damage caused to Maidenbower and Three Bridges and also aware of the process going through Mid Sussex District that will fully complete the attenuation and relieve the risk of flooding problems like of the last few days.
Cllr Boxhall said: “I’ve lived in Maidenbower for 12 years. I couldn’t get out of Maidenbower [due to flooding]. You see the damage it does. It’s wrong when there is a scheme to sort it out.”
Residents can view the plans on the council’s planning website pa.midsussex.gov.uk/online-applications and enter application number 13/03756/FUL.