Project: Titchfield Park Brook
As part of a flood alleviation scheme Ashfield District Council needed to create two balancing lakes at Titchfield Park.
These lakes would be used as temporary water storage in times of heavy rainfall to prevent flooding downstream and to reduce the possibility of flooding upstream where previously culverting of the existing stream through the park was throttling the stream and restricting its flow too much in periods of heavy rainfall.
The work was put out to tender and ICS Ltd were the successful tenderer.
The work consisted of 3 phases
Phase 1 - Consisted of striping and storing the topsoil from the park, excavating the first balancing lake to close tolerances, constructing a dam to create a second balancing lake downstream, also to close tolerances and then respreading the stored topsoil over the area of the lakes.
Phase 2 - Consisted of the diversion of the stream running through the park away from the existing closed culvert, routing it in an open culvert across the park and through the new balancing lakes, this phase also consisted of the introduction of a penstock on the outflow of the first lake to ensure that this balancing lake filled first. We also introduced a number of hard landscaping features, most notably a number of cut and dressed stone, stepping stones with flow controls between them to help control the water level of the lower lake.
Phase 3 - consisted of the landscaping of the finished project with areas of wetland on the banks of the stream , an extensive tree planting scheme of semi mature trees and a mixture of seeding and turfing of both pure grass and wild meadow.
The earthmoving section of the work was particularly challenging as the work had to take place in March and April and care had to be taken not to reduce the entire park to a quagmire during this phase as the weather was particularly inclement at this time.
The engineering also had to be accurate to ensure that the water levels on the lakes all worked to create the require storage volume from the hydraulic modelling of the site during storm conditions.
The landscaping was also quite challenging due to COVID-19 and Brexit impacting negatively on materials availability and after a very wet spring whilst the earthmoving was being done we had a dry spell during the soft landscaping resulting in us having to carry out extensive watering to get the planting established
Now that the scheme has settled down and is starting to mature the whole area looks very tranquil and is reverting back to nature in a very satisfactory manner whilst providing the necessary protection against flooding during storm conditions.