Tidal Water

References from WaStop International´s own patented products. WaStop® solves problems in a secure and efficient way.

Karehana Bay, NEW ZEALAND

A stormwater outlet into Karehana Bay in Porirua, New Zealand suffered from continuous problems with sand buildup inside the outlet. It was a costly problem involving sending someone to clean out the outlet once per week. If the sand built up too much between cleaning, and a heavy rainfall occurred the water wasn’t able to flush out of the outlet and instead built up back towards a residential area and sports ground causing flooding. The local sports ground was closed approximately 70% of the winter due to flooding. It is also a tidal area which caused problems during periods of king-tides, especially if they coincided with heavy rain.

The solution was to install a double WaStop with a rectangular flange and an overflow directly inline with the WaStops. This solution meant that if there was no sand in the valve the storm water would release as usual and run out into the harbour regardless of the tide. If sand had built up the stormwater first flows out the overflows which creates a channel quickly clearing away the sand to allow the valves to open as usual.

The sportsground is now open almost year-round and the residential area has not been affected by flooding since installation despite heavy rain and high tides.

Harwich harbour - ENGLAND

Anglian Water is one of the leading providers of water and waste water services in Europe and serves the needs of around six million industrial, commercial and domestic customers.

Aggressive tidal waters, silt and poor maintenance resulted in the existing flap valve becoming ineffective which resulted in major flooding in the area. The solution was WaStop®. The existing valve was replaced with a 600mm Wastop®.
Due to the tidal flow the installation had to be completed in just a few short hours. There was no problem with the installation and most of the time was used to remove the existing valve, dewatering, excavating, removing silt and jetting the outfall pipe. Contractor Claret Civil Engineering thought the installation of WaStop® was very simple and cost effective.

Holyhead - WALES

Holyhead in North-east Wales purchased two WaStop check valves to protect a surface water pipe against flooding.

The check valve is dimensioned for 400mm and 375mm pipes and shall protect surface water pump stations from tidal water. The WaStop® is built to manage a backpressure of 3 meter and have only a head loss of 20-40 centimeter. The check valves are also supplied with a grid that protects against intrusion.

Wapro won the job in the face of heavy competition with some of the world's biggest manufacturers of flap gates and other types of check valves. After thorough evaluation by engineers and the purchasing company, a decision was made to choose WaStop®.

The low head loss was one of the main reasons for choosing WaStop®.

Great Yarmouth, WaStop 1000 & 800mm - ENGLAND

Great Yarmouth has recently benefited from flood prevention works on its main tidal rivers that flow directly into the North Sea. At the forefront of this protection are two WaStops of 1000mm & 800mm. Installed by USL Ltd, a specialist team of commercial divers, on behalf of Aquatic Control Engineering Ltd, installation was completed within a day.
Because of the unique way the WaStop can be installed within the existing pipe it is far better protected from lateral strikes and is almost invisible to the local residents. This helps prevent unwanted attention and will not interfere with mooring boats.

Hunstanton, WaStop® 700mm - ENGLAND

Hunstanton, located in East Anglia, UK, has a long tradition for having some of the most unpredictable and severe tides in the country. Directly in the path of these tidal surges from the North Sea was a long sea outfall that was fitted with a cast iron flap valve. Over the few years this flap valve had been installed it finally succumbed and failed.
The answer was to install a 700mm WaStop directly into the end of the outfall. Fitted by Aquatic Control Engineering's team of approved specialist divers USL Ltd. It was completed in under two hours. With the WaStop installed within the existing outfall there is very little of its profile exposed to lateral wave action, unlike the flap valve.

WaStop International AB | Munkahusvägen 103 | 37431 Karlshamn | Sweden

Phone: +46 454 30 40 60 | Fax: +46 454 30 40 69 | Email: wastop@wastop.com