Post Earthquake Irrigation Checks

Updated Dripfeed Newsletter....... please send this important newsletter to all irrigator clients or neighbours in the earthquake effected area.

Below are guide-lines as to how to check your irrigation system and find out the extent of damage that may have been caused. We recommend you get a specialist to confirm things for you. You can contact the Irrigation NZ office direct 03 379 3820 admin@irrigationnz.co.nz, or board members (Stephen McNally stephen.mcnally@opus.co.nz or Ian McIndoe i.mcindoe@aqualinc.co.nz) for more information, or alternatively contact your local irrigation supplier.

Having said the above please note: Chris & Marilyn are working from home untill the IrrigationNZ offices are given the all clear (a number of cracks have appeared in the buidling) and Andrew is away on holiday (although its amazing what you can do remotely these days!)

Power

Electricity:

• Electricity is dangerous so assume live power.
• Beware of surface water around electrical hardware and fallen lines or any other unusual things.
• Turn off at mains if power cut, unless factors above make this too dangerous.  If in doubt do not touch.
• Check for obvious damage, cut or obstructed lines, misaligned motors, switch boards, transformers and poles.
• Get electrician to check out properly before turning back on.

Diesel-Petrol:

• Look for obvious damage, i.e. leaks, cut fuel lines, damaged, misplaced and/or damaged motor or tanks.
• Be aware of the presence of fumes.  Petrol fumes in a enclosed space could be explosive.

Pumps-Motors

• Check for obvious misalignment or breakage between pump and motor, pump and pipe-work.
• Ensure all elements of the pump and surrounding above ground pipe-work are secure and cannot “fly off” on start up.

Starting pumps:

• Start against closed head or as slowly as possible.
• Listen for unusual noises and stop if any other present.
• Check for leaks on suction and delivery.
• Check performance of pump for any obvious loss of performance in terms of the pressure and flow delivered.

Rivers:

• Check ground around pump station and intake, intake structures, suction pipe and river channel.

Storage Dams:

• Check carefully suction pipe particularly if through dam wall, look for signs of seepage.
• Check integrity of Dam as a whole, look for signs of seepage.

Bore Casings Checks:

• Check using a test rod - this really requires the pump to be pulled out and if the bore is of any depth a test rod could be very heavy. If the pump is not lifted then there will also be the issue of the test rod catching the rising column joints; or 
• Check using CCTV (camera) - this can be problematic if murky water is encountered.
• If the pump runs okay then the casing is probably satisfactory enough until a well driller can be brought on site.  The key will be watching the water quality at the headworks and if an increase in sand is noticed (you need to take samples to identify this) then pumping should stop.

Boreholes:

• If possible discharge to waste at head-works rather than into pipes directly.
• Check quality of water. Early indication is that water could be milky. If this is the case it is probably preferable to run to waste until it clears.  If sandy then well will need to be redeveloped.
• Cause of milky water - Fill a glass with the milky water and let it stand, if it is air entrainment (micro bubbles) the water should slowly clear from the bottom up with no sediment at all. Fine particulates can also induce milky coloured water but these will generally settle downwards.

Head-works-Valves Filters:

• Check all above ground pipe, valves and filters for obvious misalignment and damage

Pipe-work:

• Run pump against closed valves to a test pressure of at least normal operating pressure and check for loss of pressure after the pump is stopped.
• Big leaks; the system will be unlikely to reach cut-off pressure and somewhere in your system there will be evidence of surface leaking.
• Small leaks; the system will reach cut-off pressure but over a quite short period of time the pressure will reduce.
• No leaks; the system will hold its pressure.

Irrigators and Pivots:

• Check irrigators for signs of stress damage, misalignment or damage to electrical wiring.  Have a service technician make any necessary repairs.
• Check control system wiring and irrigator automation equipment operation for faults.
• Check pivot pad or linear anchor points for signs of cracking, movement or liquefication. Note: if present do NOT operate the pivot or linear and contact your service technician to make neccessary repairs.

Other systems - Fixed sprinklers and drip-line:

• Run system and identify and fix faults.