the planning process or through the wastewater tradewaste monitoring programme. Site owners are advised of the risks and their responsibilities. Engineering solutions are sought to mitigate the risks such as fitting canopies over high risk areas to avoid rainwater wash-off of contaminated material, fitting bunds around surface water sumps or fitting interceptors onto stormwater drains. Owners are encouraged to produce management plans to develop good practices and deal with accidental spillage. Staff of the Assets and Services department are notified of customer complaints and are able to respond immediately on a 24/7 basis. Pollution clear-up kits are readily available to the response crew. Temporary bunds can be deployed to contain surface contaminants and absorbent pads used to soak up spillages. There is close cooperation between Assets and Service s and the Environmental Protection Officers to respond to pollutions and to search for the source. Level of Service - Provide a reliable service. Performance Indicator – Number of dwellings, commercial and industrial buildings flooded as a result of a storm event with a five year average return interval. This indicator has only been measured for the last two years. There has been one recorded failure in that time and there was some evidence that the private plumbing contributed to the flooding. Although previously not specifically recorded flooding incidents of this nature are rare within the urban stormwater drainage areas. In May 2013 a storm over Blenheim was recorded with a one hour intensity estimated as a 9 year ARI event and a 2 hour intensity of 25 year ARI. Although this was a severe storm there were no reports of flood water getting inside dwellings or commercial businesses. Performance Indicator– Number of residential properties (dwellings including outbuildings and garages) flooded as the result of a storm event with a two year, or less, an average return interval (ARI). Dwellings Property Date Storm ARI Flooded Flooded Total Calls 23/07/2009 <5 2 5 24 25/05/2010 3 2 6 28 2/06/2010 <5 1 12 7/06/2010 <5 2 8 37 21/12/2010 9 4 4 28 28/12/2010 20 6 10 10 18/01/2011 <1.3 0 0 na 3/03/2012 1.3 0 0 na 8/08/2012 <2.33 0 9 139 12/08/2012 <2.33 0 0 12 15/01/2013 <5 1 2 21 6/05/2013 9 0 10 48 17/04/2014 <1.5 1 4 60 Level of Service - Provide a service that is timely and responsive to current needs. Performance Indicator - Percentage of complaints of flood water threatening a dwelling responded to in less than one hour. Performance Indicator - Percentage of storm related complaints received during an event responded to within four hours. Page 22