Mary Steven Park is a historic 14-hectare public park in Stourbridge, West Midlands. An ornamental lake in the park, Heath Pool, was first recorded in a map of 1750. The original pond was larger, and formed from damming and enlarging an existing pool located along the Withy Brook.
The park includes several historic buildings, amenity grassland and an ornamental lake. Dudley Council secured funding in 2014 from the Heritage Lottery Funded ‘Parks for People’ project to restore the original features of the park via a range of works.
Hafren Water was commissioned to assess the options for the removal of silt accumulated within Heath Pool. Prior to the commission, the pool was in poor condition, with excessive silt, elevated concentrations of natural organics and high suspended solid levels.
It was proposed to dredge silt from the lake as part of the restoration works. Restoration of the lake edges, through the opening of the surrounding tree canopy and planting of a reedbed around the inlet, to reduce inflow velocity and remove sediment, were also undertaken by the contractors. The dredged silt was used to restore islands and banks associated with the pond.
In order to restore Heath Pool to its original design, its current hydrological and hydrogeological conditions had first to be established. Inflows to the pool were identified to occur from natural drainage and surface water, with water levels within the pond likely to represent natural shallow groundwater.
No silt trap structures exist upstream of Heath Pool, allowing silt to have accumulated to a depth of up to 1.4m in some areas. Dredging was required to restore the waterbody. Discussions with contractors identified the need to treat the dredged silt on-site prior to disposal or re-use elsewhere, due to its high natural organic content.
The investigation undertaken by Hafrenwater indicated that the silt entering Heath Pool was derived primarily from agricultural land upstream of the park. As such, it was concluded that external flood prevention works associated with the farmland would provide sufficient and more sustainable reductions in silt migration into the pool and preclude the requirement for silt traps within the park itself. Further silt control measures were proposed through the use of part of the dredged material in landscaping the pond area.
A Pre-Dredging Report was completed by Hafren Water prior to silt removal in Heath Pool, which outlined a number of potential on-site silt treatments.
The Heritage Lottery Project at Mary Stevens Park, including the restoration and landscaping of Heath Pool, was successfully completed in 2017.