Over the week-end of the 6/7 September 2008 heavy rainfall in the Romsley area, to the south west of Birmingham resulted in over topping and partial failure of the embankment retaining the Mill Pond at Shutmill Cottage. This was the second significant over topping and failure of the embankment in a period of less than 10 years.
The resultant surge of storm water resulted in significant damage to Shut Mill Cottage and necessitated the occupants being rescued by the Fire Brigade. The flood waters then progressed downstream and caused significant damage in the village Belbroughton, approximately two miles down stream.
Following discussions with the building insurers of Shutmill Cottage, the Environment Agency and the Local Authority, it was agreed that the remedial works at Shutmill would be designed as if the Mill Pond was covered by the Reservoirs Act, even though the body of water only had an approximate volume of 2,500m3. This was agreed so as to provide additional protection to both the home owner and the properties downstream in the village of Belbroughton.
This necessitated a re-design of the outfall structure, together with the strengthening and raising the level of the embankment to meet the requirements for a reservoir.
Due to the sensitive environmental location, wide ranging ecological and flood risk studies were undertaken before the construction of a scale model of the outfall structure was constructed to verify the design assumptions.
The construction phase of the project was made more challenging by the extremely restricted access to the site with many deliveries to the site having to be double-handled in an adjacent field to allow restricted access plant to take the material to the work site.
Works were also hampered by a neighbour dispute regarding shared access which meant significant parts of the work had to be discussed and agreed with Solicitors before work could progress.
The ultimate design solution of new reinforced concrete outfall structure and sheet piling to enhance the embankment has been softened by the careful addition of brick facing to match the original cottage and Mill Pond features with soft landscaping to reflect the original cottage garden and rural surroundings.
As part of the general refurbishment of the cottage itself, required as a result of the inundation, the owner has taken the opportunity to not only improve the thermal insulation of the building but has installed air source heating and the option to have hydro electric generation through the outfall structure in the future.
The overall result of this project is not only a vastly improved structure with a benefit to the owner of the Shut Mill Cottage but it has provided protection to the many buildings and owners downstream in the village of Belbroughton.