Protecting peninsula water over summer

Paula Smith, member of the Banks Peninsula Water Zone Committee

Paula Smith, member of the Banks Peninsula Water Zone Committee

Hear from Banks Peninsula Water Zone Committee member Paula Smith about water use across the peninsula this summer.

This summer is shaping up to be a particularly dry season. Banks Peninsula streams are already exceptionally low.

As Christchurch City Council (CCC) calls for water savings in settlements with stream-fed water supplies, residents and holiday makers in rural areas should also be saving water for the welfare of Banks Peninsula’s aquatic residents, longfin eel and other native fish.

Banks Peninsula is a stronghold for many native fish species with small populations living out their complicated lifestyles in the many separate catchments with permanent and ephemeral streams. They are particularly vulnerable when stream flows get critically low.

Water supply on Banks Peninsula (Te Pātaka-o-Rākaihautū)

Fresh water is a precious resource on Banks Peninsula which is almost entirely dependent on rainfall. Even the limited groundwater below some of the valley floors seems to be closely linked to rainfall. This means the amount of water available is limited to what falls from the sky, and in a dry season like this there is less than usual to fill the tanks, water troughs and ponds, and keep the streams flowing.

Banks Peninsula has always been an important place and food basket for Ngāi Tahu and the four local Rūnanga – Te Hapu ō Ngāti Wheke / Rāpaki, Te Rūnanga o Koukourārata, Te Rūnanga o Ōnuku and Te Rūnanga o Wairewa.

Waterways are the lifelines of our communities: we depend on the waterways and the waterways depend on us.

We can all work together to address water issues, to protect mahinga kai, freshwater biodiversity, and day to day life for those living and holidaying on the peninsula.

More efficient water use is key to ensuring a sustainable future for our wai/freshwater, and through careful planning we can meet human needs and sustain a healthy ecology in the waterways.

Researching for change

The limited amount of water available for domestic and stock use is one of the key issues in our zone. On rural properties most of this comes from springs, seeps, and streams.

The zone committee’s Water Quantity Working Group is working on gathering information to help residents and farmers understand their local resource and the impact water use has on the environment and future supply.

The working group recently supported a project by some University of Canterbury students estimating water takes for stock and household use in two Banks Peninsula catchments with permanent streams.

The students found permitted water takes could potentially exceed the amount of water available. In other words, if everyone used their full allocation the streams would run dry. This would be disastrous for native fish.

Further research is required to gain a clearer picture of these effects, and how they could be mitigated. The working group and wider zone committee will continue to work with Environment Canterbury on this.

What can I do? ‘Water like you oughta!’

There are some simple things everyone can do to ensure your water use is efficient.

Start by checking your troughs, tanks, ponds, pipes, garden hoses and tap connections before we hit the summer season and fix anything that is at risk of leaking.

Find ways to minimise evapotranspiration (the process where water evaporates from the soil and other surfaces and by transpiration from plants).

Christchurch City Council’s (CCC) summer outdoor water use campaign encourages people to think about how and when we use water outdoors for things like watering the garden. Although aimed at urban residents, the tips are useful for rural residents and holiday makers as well.

Demand for water increases during summer, which can affect the ability of our water supply networks to meet the demand, especially in peak use times such as evenings. It can also have an impact on firefighting, causing CCC to impose water restrictions in some settlements to ensure the safety and continuity of the water supply.

If you must, please stick to watering your garden in the early morning or late evening, when the air temperature is cooler therefore needing less water to quench the plants’ thirst.

Alternatively, investigate ways that you can harness natures tap and reduce impacts on the environment from water use. Storage options like rain gardens or rainwater tanks can be a great start.

CCC also has some other great household water saving tips on their website.

Find out what areas of Christchurch have water restrictions on Christchurch City Council's website.

Ngā mihi nui and have a great summer but leave “enough for the eels”.


*Main image: Banks Peninsula Water Zone Committee and Water Quantity Working Group member Paula Smith (third from right, back row).