2019 Report
Here you will find attached the report commissioned in 2019 by Brighton and Hove City Council and delivered by Hydreau Consulting Engineers. Essentially the report recognises the key issues;
Dredging the Silt Out - Dredging works should be limited to the removal of the organic matter, especially that collected in the deeper areas, plus the mineral deposits brought down from the road runoff. This will have the benefit of removing phosphorous and nitrogen reservoirs from the system as well as road runoff pollutants associated with road dust etc.
Water Supply - Runoff from the major roads can not realistically be reduced unless an alternative source of water is found. If no additional water is found, the runoff from the Park Street gully should pass through a settlement tank which might be sited in the grassy area between the trees and the road.
Margins - The existing margins have suffered considerable erosion and collapse. It is unlikely that in-situ Lambeth Group clayey material can be used to seal these margins as they require substantial rebuilding. The Sarsen Stones have collapsed from their previous positions and are not now the feature they once will have been as the determining marginal feature of the pond. In order for these to be lifted, substantial works will be required.
Management - Excess wildfowl and dominant fish species are major issues. Historically, wildfowl and fish are likely to have been eaten by the villagers. Whilst this may no longer be acceptable (or healthy), the balance between water throughput and wildfowl nutrient loading must be re-established.
What is really important is the emphasis on Community/Volunteer involvement in delivering the project as well as ongoing maintenance under section 7 of the Potential Capital Works and Budgets, namely refugia construction and vegetation establishment.
1923 photo looking east showing the original positions of the Sarsen Stones (Rhodes J - Crown Copyright)