Waingaro River (Waikato)

For the river in the South island, see Waingaro River (Tasman).

Waingaro River
Waingaro Landing and mangroves at mouth of Waingaro River
Location
Country	New Zealand
Physical characteristics
Source
• elevation	150 m (490 ft)
Mouth
• location	Raglan Harbour
• elevation	0 m (0 ft)
Length	18 km (11 mi)
Basin size	123 km^2 (47 sq mi)

The Waingaro River is a river of the Waikato region of New Zealand's North Island. It flows generally southwest from its origins near Glen Afton and Glen Massey, west of Ngāruawāhia, to reach a northern arm of Raglan Harbour (see 1:50,000 map). Its main tributary is Kahuhuru Stream, which Highway 22 follows for several kilometres. Tributaries total about 170 kilometres (110 mi).[1] At Waingaro it is fed by a hot spring.

Geology

Waingaro River and hot water pump station - the pool was north of the road, but water is now pumped under the road.

The lower river flows over Puaroan age (about 150 million years ago), blue-grey Puti siltstone.[2]

Pollution

The Waingaro River is one of the largest sources of sediment in Whaingaroa Harbour, partly because it is 99 percent unfenced.[3]

Pollution has been worsening for phosphorus, though nitrogen has improved, as shown in this table of important (i.e. slope direction probability over 95% and RSKSE over ±1% pa) improvements, or deteriorations (-) in relative seasonal Kendall slope estimator (RSKSE) trends (monthly records are flow-adjusted using a Lowess curve fit with 30% span.) -[4] Turbidity is also poor.[5]

% per year	Nitrate-N	Total phosphorus	Dissolved reactive P
1993–2017	1.0	-1.0	-1.0
2008–2017		-3.4

See also

• List of rivers of New Zealand

References

1. Land Air Water Aotearoa
2. Geology of the Raglan-Kawhia Area: Institute of Geological & Nuclear Sciences (N.Z.), Barry Clayton Waterhouse, P. J. White 1994 ISBN 0-478-08837-X
3. Regional Council report on Whaingaroa Harbour Care
4. Vant, Bill. Waikato Regional Council Technical Report 2018/30 Trends in river water quality in the Waikato region, 1993-2017.
5. "Waingaro River (Pukemiro) at Ruakiwi Rd Off SH22 River Quality". Land, Air, Water Aotearoa (LAWA). Retrieved 18 January 2019.

• "Place name detail: Waingaro River". New Zealand Gazetteer. New Zealand Geographic Board. Retrieved 12 July 2009.
• New Zealand 1:50000 Topographic Map Series sheet BD32 – Raglan

External links

• most of the river is close to Ohautira and Waingaro Roads, so many images are available in street scene on https://maps.google.com/
• water quality at Ruakiwi Rd LAWA WRC
• water level at Waingaro
• [1], [2], [3] - National Library 1910 photos of Waingaro Landing, Waingaro Bay (note the 1900 road to the Landing on the hillside) and Waingaro Estuary.
• 1955 Waingaro Landing aerial photo - the foreground shows part of the Kerikeri River arm of the harbour, which is over 3 km long. The Waingaro River joins the estuary in the middle left of the photo.
• Photo of oil launch 'Nita'.
• 2012 Estuarine Vegetation Survey - page 15 describes the wildlife in the Waingaro and Kerikeri River arm of the harbour.

37°44′36″S 174°57′30″E