Pomahaka Catchment Project

Farmers in the large Pomahaka River catchment have formed a group to focus on improving river water quality. Stream sampling and analysis are being used to identify problem areas and new management practices are being tested. In a project co-ordinated by NZ Landcare Trust they have worked to bring the majority of land users, non-farming stakeholders and town dwellers on board. Some significant gains have been made. 

The Pomahaka Catchment in south-west Otago is some 2060km² of diverse terrain and land uses. The main waterway is the Pomahaka River, which is about 100km long and drains into the Clutha River. The upper half of the catchment is steep to mountainous, extensively farmed tussock country, predominantly sheep and beef. The lower catchment is pastoral rolling hill country and more intensively farmed with dairying in favourable localities. 

Annual rainfall almost doubles from the low end of the catchment to the top and while it is relatively high and reliable, waterways are often contaminated as a result of common farming practices, such as:

• Mole and tile drainage
• Uncontrolled runoff from races
• Stock accessing waterways
• Winter feeding of crops on saturated paddocks 

The size of the catchment and its diversity mean that there had been no community cohesion and even within small localities, farmers at one end of a tributary seldom knew farmers at the other end. 

In 2012 the Otago Regional Council was concerned by the pressing need to halt the deterioration in water quality. It engaged the NZ Landcare Trust to look at the possibilities for bringing farmers together and formulating a plan for the catchment. This was carried out in 2013 and began with a series of meetings that included all stakeholders; Regional Council, Federated Farmers, Fish & Game, fertiliser reps, DOC, DairyNZ, Beef & Lamb NZ, as well as farmers. 

Dairy farmer Lloyd McCall attended the second of these meetings and says they were very useful for sharing information and hearing others’ points of view. “After one of those meetings the Regional Council put up some graphs of water quality and that was a watershed moment for me because the test results for N, P and E. coli in my area were pretty bad. I realised that the only way to fix it was for farmers to buy into the whole process – they had the desire to improve the water quality but they had to do it for themselves and not the Council or anybody else,” he says. 

“So in June 2014 I called a meeting of local people to see what they thought and they decided to set up a water care group and created a plan. The tests that had been done by the Council were just a few spot tests on the river and we didn't know what the water quality was like anywhere else.” 

The group then decided to regularly test the river and its tributaries to identify and track seasonal changes. The number of sites depended on membership – fees were $250 per farm, mainly to pay for the services of a water quality scientist independent of the Council. 

“We started testing at about 15 sites and the results were fascinating. Initially they showed that the problem wasn't only happening on the lower land areas around dairying, it was also from the upper areas and across the whole catchment,” says Lloyd. 

“We found that there were higher levels in the headwaters and that there were lots of individual one-off events, such as an E. coli spike, at one site but not at any of the others. The sites were tested every six weeks and they got five tests in autumn 2014 and 2015. There was high E. coli in the sheep farming areas in late spring whereas dairy farms tended to have high E. coli in the autumn.” 

On a couple of occasions the whole catchment had a large burst of phosphate in the water samples. It was established that it had happened after two or three weeks of dry weather followed by a flush of rain. It was found that if fertiliser had been put on and landed onto critical source areas (like hollows) the rain trickled down the hollows, taking granules with it into the streams and then into the Pomahaka. 

As well as encouraging farmers to buy into the idea of improving water quality, the group wanted to monitor bank erosion, count fish and other flora and fauna, publicise and encourage best practices and let the public know about positive happenings on the river. 

They also wanted to generate land and environment plans on a few sheep and dairy farms, and provide a couple of focus spots on the river for school groups and the community to take ownership of and enjoy. “We put short items in a local newspapers to raise awareness of water quality issues, such as grazing crops from the top of the paddock to the bottom, fencing waterways, keeping a riparian margin by the crops, and we summarised and publicised the Telford winter grazing program,” says Lloyd. “It wasn't just for farmers to recognise problems and know about solutions, it was also for the local townies to understand them and see we were doing something about them, so both town and country would buy into it.” 

Since then the Water Care Group has become an Incorporated Society. It has 111 members and is aiming for 150 (there are about 320 different farming entities in the Catchment) with membership from each of the three main regions of the Catchment. This season about 120 water tests are planned, and about 10 different wetland filtering systems are to be trialled, funds permitting. 

Promotions will continue with signage along roadsides indicating Water Care Group initiatives. Lloyd says they want people to drive past and know that farmers and others are doing something positive about water quality. “We want everyone to know what is in our waterways and how to improve them. Our ultimate aim is to have the Pomahaka River recognised as having top water quality so that future generations can enjoy it as we have done. Our values include profitable, sustainable agricultural businesses thriving alongside recreation and tourism in a pristine environment, healthy ecosystems and fish life,” he says. 

“We believe in education via encouragement rather than enforcement, and so far we have been getting good gains. There have been changes in attitude, big improvements in winter grazing management, more grass berms to trap silt and E coli. The deterioration has stopped and Regional Council test results show that in most cases there has been an improvement and the key thing is that we are doing it over a large area, not just one small corner of the catchment”. 

Much of the work carried out so far has been facilitated and supported by the NZ Landcare Trust. Following the success of their initial scoping exercise the Trust won a grant from the Sustainable Farming Fund for a three-year project to connect landowners and stakeholders within the Catchment, and to help farmers investigate and adopt appropriate management practices to reduce nutrient loss and improve water quality. 

Craig Simpson, the project manager for the NZ Landcare Trust, agrees with Lloyd that the decline in water quality has halted and the situation in the Catchment is slowly starting to improve. “The initial study looked at what improved management practices could be introduced and at what else could be done to connect the community together to do a whole-of-catchment scale project. We are currently halfway though the Pathway for the Pomahaka Project, which started in July 2015,” Craig says. 

“So far there has been a good uptake of the main messages. We have talked a lot about changing farming practices, keeping stock out of waterways, grazing practices like keeping away from critical source areas or strategic grazing starting at the top of the paddock instead of the bottom. We are also starting to notice more emphasis on riparian margins, avoiding stock in waterways, and there have been big learnings in areas such as fertiliser application.” 

“The Water Care Group itself has driven a lot of these changes and much of our job is to support them. One of the keys to this project being successful is farmers talking to farmers and changing perceptions. For example, one time there was the fertiliser truck spreading urea very close to a creek, and someone local took water samples to test and the nitrogen level was maybe 70 times higher than it should have been. That kind of message is more readily accepted coming from another farmer rather than from the Regional Council.” 

Craig says there have also been changes in social dynamics because what was thought to be a dairying problem is now known to be a problem throughout the catchment. There had been a disconnect between the upper part of the catchment and the lower part - but now there is a realisation that farmers are all in this together and all part of the same catchment. 

”There is great community spirit and the farmers are driving the project themselves. We facilitate meetings and organise field days but a lot of the uptake comes from the farmer driven approach which is an area that Landcare Trust specialises in,” he says. “We are now seeing greater use of riparian strips, better grazing practices in winter, and better effluent management. This includes having adequate storage so that it isn’t necessary to apply effluent in wet weather, ensuring that the pond doesn’t leak, and suitable gear to apply at lower rates.” 

Last year a number of farm environment plans were generated; land environment plans for sheep and beef farmers, and sustainable milk plans for dairy farmers. These include such strategies as careful timing and placement of fertiliser to avoid runoff, and not working critical source areas where rain will flow and pick up sediment and nutrients. Leaving them unworked means they act as buffer zones and trap sediment. More environment plans will be completed this year. 

Craig says that major change in such a diverse community takes time but excellent progress is being made. “The Water Care Group is doing a really good job and they have built up a very good picture of what is going on in the waterways and have traced some of contaminants to fertiliser application and so on. The programme is going well and we have got some really great deliverables so far but there is still a lot of work to be done,” he says. 

“A lot of our project has been about helping to explain to farmers what their obligations are under water plans, and the Group is looking at testing some constructed wetlands and bark filter beds to improve the water quality leaving some farms so that those farms can meet their water plan limits. We are just starting to get funding for this and there will be a trial over the next year looking at effectiveness and suitability for this area. There is a very good feeling now in the catchment and we are helping to bring the community together, and I think that is probably the biggest benefit of the Project.”