Posts
August 2022
Fish Passage
Ensuring that construction works in or adjacent to waterways do not have adverse impacts on the freshwater species means that the fish passage needs to be maintained and fish salvage may be required. Fish salvage can be costly and sometimes neglected or forgotten, however, this is important as failing to meet the requirement can result in enforcement actions being taken by the local authority. There have been prosecution cases in Canterbury associated with fish mortality. The contractors’ lack of awareness is often the problem. Ensure that your contractors and subcontractors fully understand the requirements.
January 2021
What causes effluent ponding?
Serious effluent ponding can lead to enforcement actions and fines. Effluent ponding is often caused by negligence and accidents. More often than not, these accidents are foreseeable and avoidable.
Effluent ponding is caused by heavy discharge or stationary discharge of effluent (or applying on saturated ground). Your irrigator may not be moving fast enough or not moving at all. Below are some of the common causes of effluent ponding.
blockages (e.g. gun on centre pivot not moving)
low pressure caused by solids or split nozzles
nozzles are too big
speed is too slow
irrigator gets stuck in hollows
application rate is set too high (e.g. centre pivot)
K-line pods running too long
applying effluent too heavily on slopes causing runoff and ponding
applying effluent onto wet ground (and puddles)
Solutions may be to monitor the discharge (fail-safe system often saves you), separate solids well, know your application rate, not apply when wet (you have enough effluent storage?), use splash plates on travelling irrigators to avoid the hose-like discharge, etc.
Educating your staff is also important!
August 2020
Fish screens
Ecan will be inspecting fish screens in Canterbury in line with Schedule 2 of the Land and Water Regional Plan over the next 5 years. This means some fish screens in Canterbury will need upgrading or replacement in order to comply with the newly applied criteria. If it's a pump take, it is relatively simple to comply. If you have an intake with a screen (e.g. rotating drum screen or vertical screen) and fish bypass, you will need to take into account the screen aperture size, screen open area proportion, approach/through velocity, sweep velocity, size and location of bypass as well as screen angle. Rock bunds and infiltration galleries are tricky to prove effectiveness. Finding the right solution is important.
June 2020
End of water year
The 2019-2020 water year ends at the end of this month. If your water data doesn't seem correct with data spikes (which make you look like you're taking way more water than actual) you might want to check if hot wires are affecting the pulse of your recording device before you pay someone to check the problem. Data spikes are common problems and they trigger 'non-compliance' because water usage is not recorded accurately. Removing or turning off hot wires from the vicinity of the water usage recording device can sometimes solve the problem. If not, contact the experts.