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The way we use our land creates legacy effects

The way we have managed our land and fresh water has negatively affected the state of New Zealand’s freshwater environment (see A potted history of freshwater in New Zealand). Natural factors, such as climate, geology, and topography, determine how human pressures affect the state of water bodies. This means that water in different catchments responds to pressures in different ways, so we need to consider the specific context for each water body.

It can sometimes take decades, or even longer, for water (and any contaminants it contains) to cycle from the earth’s surface through the ground to aquifers, and back to surface-water systems – this delay is referred to as lag time. For example, in the Te Arawa (Rotorua) lakes, the average lag time is generally around 50 years – and is over 100 years in one catchment (Morgenstern et al, 2015). This means some effects we see today are legacies of past activities, and the impact of our activities today, both positive and negative, may not be seen in our waters for decades.

A potted history of fresh water in New Zealand

About 1250 – 1300 AD – First people arrive in Aotearoa New Zealand from East Polynesia.

1300 – 1800 – About 50 percent of the country’s forests destroyed by fire (Quinn & Phillips, 2016).

1840 – Organised settlement of New Zealand by Europeans begins. Over the next half-century, more forest is cleared to make way for urban and rural land uses (Quinn & Phillips, 2016).

Mid-to late1800s – As towns and industrial activity grow, sewage and industrial waste are piped directly into rivers and streams (NIWA, nd).

Late 1800s – Large-scale irrigation in New Zealand begins (Irrigation New Zealand, nd).

1903 – Water Power Act 1903 introduced, giving the Crown the sole and unfettered right to use water in rivers, streams, and lakes for generating electricity.

1915 – Swamp Drainage Act 1915 introduced, leading to the draining of extensive areas of wetlands for pastoral use in the 1920s – around 90 percent of wetlands to date (Ministry for the Environment, 2007).

1940s – Catchment boards established under the Soil Conservation and Rivers Control Act 1941 to reduce soil erosion and prevent damage from floods.

1953 – Waters Pollution Act 1953 introduced, creating the Pollution Advisory Council to regulate end-of-pipe discharges into water.

1967 – Water and Soil Conservation Act 1967 sets in place a single consenting system to regulate water use, including discharges.

1975 – Waitangi Tribunal established. The Tribunal and Treaty processes become highly influential in shaping policy about fresh water, particularly in better recognising Māori rights and interests in fresh water.

1981 – Wild and Scenic Rivers Bill passed into law, enabling water conservation orders to be created in the face of mounting pressure to dam rivers for hydroelectricity schemes.

1987 – For the first time, dairy farming exceeds sheep farming as New Zealand’s highest-value primary industry export (Te Ara, nd).

1991 – Resource Management Act 1991 introduced, creating an integrated consenting system for land, water, and air, guided by the principle of ‘sustainable management’. Point sources of water pollution become increasingly tightly controlled, sparking investment in upgrading wastewater treatment.

2009 – Land and Water Forum established as a cross-sector collaborative with the objective of developing a common direction for freshwater management in New Zealand and providing advice to government.

2011 – National Policy Statement on Freshwater Management introduced, with the primary objective of improving freshwater management by regional councils.

2014 – National Policy Statement (NPS) on Freshwater Management amended, and national bottom lines for water quality established through the National Objectives Framework. Regional councils have until 2025 to implement the NPS.