Yorkshire Water has published a further report about the June 2007 flooding in Hull in response to a request from Ofwat. The report, Humbercare Sewerage Network Analysis, examines the flooding in Hull last year and the performance of the sewerage network in the city. Following the flooding Yorkshire Water were asked by Ofwat to investigate, model and explain the performance of its drainage assets in Hull.
The report focuses on the performance of the ‘Humbercare’ system (East and West Hull Pumping Stations, Saltend Waste Water Treatment Works and the connecting transfer tunnel) and its impact on the public sewerage network connected to it. It also comments on the operation of Bransholme Surface Water Pumping Station.The report shows that the flooding in Hull was caused by the massive amount of rain that fell on the city during the month of June 2007. It also says:
Humbercare, which includes East and West Hull Pumping Stations, the tunnel and Saltend Waste water Treatment Works, was criticised after the floods but the MWH report shows that it provided a 1 in 30 level of protection to over 92% of the city in June last year; 1 in 30 is the industry standard. This is a level of protection which would be found in most UK cities.
The modelling study also shows Humbercare was providing a slightly reduced level of protection in the city compared to the level provided by our network before Humbercare was built. The £16 million investment, announced just after the floods, will improve the level of protection to the highest standard ever provided in the city. Yorkshire Water says the work will be finished in autumn 2009.
In 18 March 2008 Ofwat requested additional clarification regarding a number of issues highlighted in an expert opinion report prepared by consultants. Wrc on behalf of Ofwat. The Yorkshire report has clarified the performance of the drainage in Hull in June 2007 and demonstrated the improvements that the work currently being implemented will bring.
According to Ofwat it is likely that more detailed work, which is now proposed, will lead to a greater understanding of the level of protection appropriate for Hull, and opportunities for local improvements in the sewerage system. The regulator says it expects Yorkshire Water to progress this work and incorporate its investment proposals in the current round of business plans being prepared in anticipation of the 2009 water and sewerage services price review.