Upper Clutha Lakes Trust secretary Julie Perry considers water issues in the Upper Clutha district in this week’s Protecting our Water column.
The Environmental Reporting Act of 2015 requires the government to produce a report on air, atmosphere and climate, fresh water, land and marine every three years.
The 2019 report, Environment Aotearoa, discusses the most important issues that affect the health of our environment today.
Key issues for the Upper Clutha include:
Unique native biodiversity under significant pressure from introduced species, pollution and physical changes to our landscapes.
Draining wetlands and clearing land has degraded a range of benefits provided by native vegetation, accelerated soil loss and affected our waterways.
Waterways are polluted by excess nutrients, pathogens and sediment.
Using freshwater for hydro-electric generation, irrigation, domestic and other purposes changes the water flows in rivers and aquifers.
Changes to our climate are already being felt, with wide-ranging consequences for our culture, economy, infrastructure and native species.
The local community has an important role to play in delivering improved outcomes for lakes and other waterways.
The Upper Clutha Lakes Trust is focusing on water bodies and their catchments upstream of the confluence of Luggate Creek and the Clutha River.
Key factors impacting this catchment area include urban growth, land use changes and tourism. Existing regulation, processes and resourcing are proving inadequate, as demonstrated by the following examples:
Ongoing non-compliance of the Hawea wastewater treatment plant has resulted in the release of large volumes of nutrient and bacteria-rich liquid.
The consent under which the facility operates does not require monitoring of the Hawea River below the plant.
The 2018 Guardians of Lake Wanaka report to the Minister of Conservation noted the Overseas Investment Office required the new owner of Hunter Valley Station to increase stock numbers by around 50%.
The Guardians were dismayed that questions of environmental impacts of the proposed increased production were considered irrelevant.
These impacts were expected to include increased run-off of nutrients, silt, herbicide and pathogens into Lake Hawea and into that catchment of Lake Wanaka between the Neck and Camp Creek.
Sediment and pollutants from urban development: Northlake run-off events have discoloured the Clutha River; Meadowstone Alpha Series overflows into Bullock Creek and Lake Wanaka.
Other sources of stormwater run-off contaminate lake areas such as Roy’s Bay.
Rural run-off events such as those at Reko’s Bluff, upstream of Luggate Bridge, which resulted in riverbank gullies of up to 30m wide and 20m deep, damaging Newcastle Track and sweeping thousands of tonnes of silt, gravel and boulders into the Clutha River.
The Reko’s Bluff erosion events followed the conversion of terrace dry-land vegetation from tussock and native shrubland to irrigated pasture.
The Wanaka Water Project is working with the community to develop an integrated catchment management plan, a road map for future water management.
Securing enduring aquatic ecosystem health for the Upper Clutha catchment will involve evidence-based management of the lakes and catchments; funding for research and resources to support evidence-based decision making; and leadership and engagement across rural, urban, commercial and tourism sectors.