distribution pumps. A total storage capacity greater than 20,000 m is around average daily3 demand and two thirds of peak day demand. Blenheim Reservoirs Capacity Year (m)3 Installed Weld Street 5,700 1971 Redwood Street 90 1996 Forest Park 175 2005 Blenheim Low Level 10,000 2010 Middle Renwick Road WTP 950 2009 Central WTP 2,900 2011 Blenheim High Level 2,000 Proposed Blenheim Reticulation The Urban Growth Strategy has provided a coherent plan of growth pockets for the anticipated population growth to around 2030. Following the Canterbury earthquakes the strategy has been revised to avoid areas that maybe vulnerable to liquefaction and the effects of lateral spread. Seven growth pockets have been identified to the west and north of Blenheim that have been zoned for urban residential development. The strategy will be vital to the design of future upgrades to the reticulation network. The main trunk mains emanating from the treatment plants at Middle Renwick Road and the Central WTP are connected to the trunk main in the Taylor River corridor transferring bulk water supplies to the south and west of the town. It is likely this will be the source for any major developments to the west. A dynamic hydraulic model exists for the Blenheim water supply and will be used extensively to both advise the development of the growth strategy and in the subsequent detailed design of reticulation pipework. 3.3.2 Picton Sources The three bores at Speeds Road are capable of delivering the consent limit of 58 L/sec. The Essons Valley WTP has been upgraded to meet the Drinking Water Standards and has a design capacity of 35 litres/sec. In theory this would offer a maximum supply volume of 8,035 m per day. However in drought years both the storage capacity of Barnes Dam and aquifer3 below Speeds Road can be adversely affected and restrict the total deliverable volumes. Both desk top studies and site investigations have been undertaken to find a further reliable high quality water source to meet Picton’s current drought demand and future growth demands. Exploratory bores have been drilled at Grahams Valley, Speeds Road and Linkwater but with unsatisfactory yields. The nearest reliable source has been determined as the Wairau Aquifer between Spring Creek and Tuamarina. To connect this prospective source to the main Elevation Reservoir would require a trunk main of around 19 km in length at a budget cost of $13M. There are no plans to use this source at this time whilst other demand management techniques are evaluated. Picton Treatment A treatment plant upgrade is being planned for the Speeds Road site to meet the maximum output capacity. Design is currently underway. Some early preparatory construction has been undertaken. The main contract and construction is planned for 2015/16. Picton Reticulation A dynamic mathematical model has been created for the Picton water supply system. Future growth has been simulated within the model and a number of upgrades have been identified to3 increase supply to low pressure areas. The model has been used to identify areas where pressure reduction can be implemented to help to reduce demand. The first pressure management zone in central Picton was established in 2013/14. 3 O:\Corporatereference\WaterReticulation\Picton\Modelling\07pw Page 47