The Waitakaruru River is a river of the Waikato Region of New Zealand's North Island. It flows initially north before turning northwest across the northwestern corner of the Hauraki Plains, reaching the southwestern corner of the Firth of Thames close to the settlement of Waitakaruru.
Grey mangrove, or mānawa, has rapidly colonised the estuary since 1940, due to sediment deposited by the rivers and climate change.
Pollution In its lower reaches the river is not fit for swimming, as the nitrogen and phosphorus pollution levels are many times those of the natural river.
Pollution has generally been worsening, as shown in this table - +Relative seasonal Kendall slope estimator (RSKSE) trends (% per year). Important (i.e. slope direction probability over 95% and RSKSE over ±1% pa) improvements, or deteriorations in bold.ConductivityTurbidityVisual clarityTotal nitrogenNitrate-NAmmoniaTotal phosphorus (provisional)Dissolved reactive PEscherichia coli1993–20171.1–1.81.9–1.5–1.8–3.6–1.6–0.7–2.02008–2017–0.4–4.27.6–2.6–1.5–3.0–3.9–2.3–7.3 Monthly records are flow-adjusted using a Lowess curve fit with 30% span.
See also List of rivers of New Zealand
References
External links 1:50,000 map 1991 hydrological report and map of catchment 2006 estuary vegetation survey