Catchment Management Plan and River Flow Modelling
For the past three irrigation seasons, MCG has engaged Dean Olsen of Freestone Freshwater to undertake low flow monitoring on the Manuherekia River throughout the irrigation season while the flows are typically lower to see the ecological impacts.
You can read the full report on our website here.
As MCG members, you will know that we developed Catchment Management Plan proposing 1,100 at campground and residual flows at the tributaries.
MCG has contacted irrigation companies and sub-catchment members as we propose full implementation in the upcoming irrigation season, you can find more about the CMP here.
Significant Stock Water Schemes Developed within the Catchment
There are two groups of farmers who have taken the initiative to create community stock water schemes within the last 12 months which have some seriously good win: win outcomes for their businesses and for the environment.
The first one was set up in the northern end of the Ida Valley and in the top of the Manuherekia catchment called the Hills Creek Stock Water Scheme. This is 169,000 stock units with 37 users.
The second one is in the Wedderburn / Gimmerburn area of the Maniototo and is called the Wedderburn Stock Water Scheme. This is 113,000 stock units with 37 water users.
These stock water schemes have been initiated by the Directors of the Hawkdun Idaburn Irrigation Company to demonstrate water use efficiency and help in the process of irrigation right consent renewals going forward.
They are delivering high-quality stock water on a year-round basis and all via gravity.
It is one of the cheapest stock water schemes to be developed in NZ at present with development costs between $11 to $15 per stock units and annual running costs of around 25 cents per stock unit.
The stock water schemes were made possible through an innovative funding model that allowed different farmers to access different amounts of funding through the stock water company to suit their individual circumstances. This was made possible through the BNZ Green Loan funding product lent to the stock water schemes.
There are expected to be significant improvements in productivity and grazing management by having reliable high class stock water. Currently there are some grazing systems that are unable to utilise the feed that is grown because of the inability to provide high-quality stock water.
This stock water scheme will allow much better grazing management throughout the district and there will be enhanced financial returns to the farmers as a result.
Environmental Benefits
1. Estimate of the water savings
Under the previous stock water arrangements, the Hawkdun Idaburn Irrigation Company delivered 92 litres per second to the Hills Creek stock Water Scheme catchment and 84 litres per second to the Wedderburn stock water catchment.
These will have water takes of 10 litres and 7 litres = 17 litres per second compared to the previous 176 litres per second. This is a 900% + improvement in water use efficiency.
The previous stock water was provided through open races where there was significant evaporation loss and loss into the soil from the open races and what is delivered is generally often of poorer quality. It has also extended the area previously serviced by the open stock water races.
Some stock water is also currently sourced from creeks and storage ponds which will be significantly reduced.
2. Estimate of Power Savings
There are a number of farmers who currently draw some of their stock water from a bore and use electricity to do this. The new stock water scheme will be entirely supplied by gravity. This will result in a significant saving in electricity and costs associated with maintaining electrical pumps. Any saving in energy costs is a benefit to the environment.
3. Confirmation of reduced reliance on the waterways
When this stock water scheme is in place there will be the ability to fence off creeks from cattle and create wetlands that are not required for stock water purposes. Currently all water ways and dams form part of the stock water system.
It will greatly enhance the conservation and biodiversity outcomes by having the opportunity to remove livestock from water ways within the catchment.
AGM
Manuherekia Catchment Group wishes to advise that our Annual General Meeting will be held 4:30pm, Wednesday 21 October at Matakanui Rugby Clubrooms, Omakau Domain.
We’re on the look out for one new committee member, if you are interested in joining our committee then please reach out to Clare Hadley, gm@mcg.org.nz or one of our committee members.
Ecofund Announcement
The Manuherekia Catchment Group is pleased to announce that our application to the Otago Regional Council's Ecofund has been successful. The funding will support ongoing willow maintenance at two of the wetland restoration sites established through the Waiora Manuherekia project – Hills Creek and the Lauder Rail Trail Bridge site. This funding will ensure professional follow-up weed control continues alongside the invaluable efforts of our volunteers, helping to protect the restoration work already achieved and giving the native plantings the best opportunity to thrive.
