The official version of this document can be found via the PDF button.
The below content has been automatically generated from the original PDF and some formatting may have been lost, therefore it should not be relied upon to extract citations or propose amendments.
1240/5(4746)
WRITTEN QUESTION TO THE MINISTER FOR TRANSPORT AND TECHNICAL SERVICES BY DEPUTY A.K.F. GREEN OF ST. HELIER
ANSWER TO BE TABLED ON MONDAY 21st SEPTEMBER 2009
Question
Following a site visit by the Minister and officers, would he outline what measures, if any, will be taken to prevent a fifth instance of flooding at the propriety known as La Maison de L'Etacq, St Ouen from water which is discharged from a Transport and Technical Services' culvert on La Route de L'Etacq and also indicate time scales for any proposed work?
Answer
The Transport and Technical Services Department does not currently propose to undertake any works on the culverts under Route de L'Etacq at the bottom of Mont Huelin in St Ouen, as it is not believed that these culverts are the source of the flooding of Maison de L'Etacq.
The culverts under Route de L'Etacq have been surveyed and it has been determined that they have the capacity to cater for an extreme rainfall event on the Mont Huelin catchment. However, if their capacity were to be exceeded, water would spill from the upstream inlet chamber on the northern side of Route de L'Etacq and be directed eastwards by the falls of the road down Le Chemin de la Brecquette and therefore away from Maison de L'Etacq.
Photographs from the most recent rainfall event that caused the flooding of this property, taken in December 2008, clearly showed significant volumes of water from the private stream and culvert adjacent to the Parish road, Mont Huelin, discharging onto Mont Huelin as a result of the private culvert being blocked with debris that had built up over a significant length of time. Due to this volume of water discharging onto Mont Huelin and then onto Route de L'Etacq, the road gullies in Route de L'Etacq became inundated and blocked with debris from the flow, resulting in flooding of Maison de L'Etacq.
The road gullies on Route de L'Etacq, at the bottom of Mont Huelin, are not designed to deal with the volumes of water, together with the debris that were discharged onto Route de L'Etacq from Mont Huelin during the rainfall event in December 2008. It was clear from subsequent site visits by Officers of the Department that the inlet to the private culvert on Mont Huelin had not been cleared for some considerable time, which significantly reduced the ability of the culvert to accept flow from the catchment, resulting in the water discharging onto the road.
The solution to this recurring problem is for the owner of the private culvert and stream on Mont Huelin to carry out regular cleaning and maintenance of not only the culvert entrance, but also the upstream channel of the stream, to prevent future discharges of stream water onto the road.
The Department's Officers suggested to the owner of Maison de L'Etacq that to help mitigate the impact of any future flooding events on the property openings be formed in the roadside wall that would discharge any water build up in the road across the gardens to the fields to the south. The Department's Officers are unaware of any such works having been undertaken to-date.