Stormwater Management
Sustainable Urban Drainage Systems
The emphasis on sustainable urban drainage systems (SUDs) by local authorities to deal with stormwater from development of Greenfield sites is becoming increasingly important. The aim of SUDs is to allow attenuation of peak water flows, thereby reducing the impact of stormwater runoff on the environment.
Discharge to watercourse
Where a site is not connected to a public stormwater sewer then there are a number of options available. The first option is to discharge to a watercourse in close proximity to the site. Where this is being proposed, it is necessary to carry out detailed calculations in order to design the attenuation system required. A lack of understanding by many consultants can result in excessive amounts of attenuation volume being recommended at a considerable cost to the developer.TEC Ltd have the expertise to carry out these calculations accurately, thereby minimizing expenditure on the attenuation system.
Discharge to foreshore
Where there is access to the foreshore then it may be an option to discharge stormwater to the foreshore. TEC Ltd can assess the feasibility of discharging to the foreshore based on all available environmental data. Where discharge to the foreshore is proposed, TEC Ltd wil apply for a foreshore license from the dept of communications, marine and natural resources.
Discharge to ground
Where there is no public sewer or any other watercourse to discharge stormwater into, it may be possible to discharge to ground via percolation trenches. TEC Ltd have the expertise to design these trenches based on BRE digest 365, the guidance document for design of soakaway systems.
Discharge to sewer
Where there is a public sewer with a low capacity, Local Authorities may request attenuation prior to discharge. TEC Ltd design attenuation systems in such circumstances.