A Self-Cleaning Screen (to exclude fish and debris) was supplied by AWMA and installed on the Balmoral 2 Intake in July 2017.
New Zealand's Amuri Irrigation Company Limited (AIC) currently irrigates 28,000 hectares of land within the Waiau and Hurunui catchments. The original irrigation schemes (Waiau, Balmoral and Waiareka) all fall within the Amuri Basin and are operated by AIC.
The Cylinder style Intake Screen consists of three components:
- Turbine driven Cylinder Screen
- Connecting Elbow
- Swivel Tee
The Connecting Elbow and Swivel Tee allow the screen to be easily lifted out of the water.
AWMA manufacture fish-friendly intake screens with a degree of customisation available. Configurations include ‘T’ or drum style screens that may be mounted on retrieval systems such as a custom framework with electric motor-driven winch or submergible pontoons.
The key benefit of AWMA’s intake screens is the self-cleaning function that eliminates any debris loading or suspended solid build-up from the screen. The self-cleaning function on the cylinder screen utilises one exterior and one internal brush that cleans the screen as it is rotated.
Propeller driven screens operate automatically whenever the flow in the suction pipe exceeds a minimum flow velocity, turning an impeller that rotates the screen through a gearbox arrangement.
The Cylinder Screen material and design dictates very low maintenance requirements. The screen medium is wedge wire, available in a variety of slot sizes to suit the application. Manufactured from Grade 304 stainless steel the screen is extremely strong and durable.
The Canterbury area of New Zealand has documented ‘Good Practice Guidelines for Fish Screening’. This government document notes Cylindrical Screens:
- have been widely applied, have a good performance record and have been accepted by the resource agencies as positive barrier screens;
- have a proven cleaning capability that removes debris off the screen;
- result in lower maintenance costs;
- are easily accessed if maintenance is required.
Andrew Spencer, Asset Manager of Amuri Irrigation Co. stated; “The AWMA supplied screen on Balmoral 2, has performed very well over the last season. The combination of its stainless steel wedge wire screen, and, both internal and external brush cleaning system, has required minimal maintenance, in one of our irrigation races which has periods of the season with significant weed.”