(04) 4733124 info@h2o.co.nz

Blocked Stormwater

Stormwater drains are most often blocked by material such as sand, dirt, mud and leaves. This material is either washed into the pipe via the roof downpipes or sometimes at ground level in storm conditions. Ground drainage coils can also contribute to contamination by carrying clay into the stormwater lateral. Usually deposits slowly build up until the pipe diameter is severely reduced and efficiency drops to a point where a complete blockage occurs seemingly all of a sudden. Blocked stormwaters can be a the cause of basement dampness, ground subsidence and subsequent damage to other structures.

Stormwater drainage is quite separate from sewer drainage as a legal requirement. Where the stormwater ends up varies with property age and location. Older homes may have soak pits – holes in the ground filled with large rocks or concrete slabs where local ground drainage is suitable. Eventually leaves etc… will block the ability for soakage and the pit will require maintenance. Other older properties drain to kerb outlets. These can be damaged by subsequent footpath work, cable installations and retaining wall subsidence. Also root invasions are a common source of problems. In areas such as Lower Hutt drainage may end up in streams. Stream banks can erode and flood events bury these outlets.

Newer properties will usually drain to a Council main. The most common source of problems for these is siltation and root invasions. A recent issue has been hardened cement wash washed into ground drains when exposed aggregate paving is installed. Schools and public places have issues with litter and items such as tennis balls, plastic bottles and cans entering drains. These pose a special challenge but one H2O is able to meet.

This is where H2O  Contractors can help !

H2O Contractors have high pressure water jetting units (hydrojetters) that are extremely effective at removing all manner of blockages from dirt to cement wash. A downstream access point is always preferred and quite essential for large diameter pipes. Our wide range of nozzles can remove stubborn blockages whenever pipes are relatively undamaged. If pipes are damaged our CCTV and electronic location equipment can be invaluable for isolating areas to be repaired.

H2O offer a wide variety of hydrojetter trucks with flows ranging from 30 to 400 litres a minute and pressure from 1,500 psi to 12,500 psi. We can therefore clean pipes ranging in size from 50 mm up to greater than 1 m diameter. Add to this a capability of holding up to 500 m of drain cleaning hose, a range of root saws and rotating nozzles, CCTV targeting of blockages and tanker capacities up to 7,000 litres and it is obvious H2O can meet almost any challenge.