![Waitetuna valley from Plateau Rd](https://upload.wikimedia.org/wikipedia/commons/c/ce/Waitetuna_valley_from_Plateau_Rd.jpg)
The Waitetuna River is a river of the
Waikato Region
Waikato () is a local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton City, as well as Hauraki, Coromandel Peninsula, t ...
of
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
's
North Island
The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...
. It flows generally northwest from its sources southwest of
Whatawhata
Whatawhata, previously also spelt Whata Whata, is a small town in the Waikato region on the east bank of the Waipā River, at the junction of State Highways 23 and 39, from Hamilton. Te Araroa tramping route passes through Whatawhata.
Histo ...
to reach the southeastern coast of the
Raglan Harbour
Raglan is a small beachside town located 48 km west of Hamilton, New Zealand on State Highway 23. It is known for its surfing, and volcanic black sand beaches.
History
The Ngāti Māhanga iwi occupied the area around Raglan in the lat ...
.
Geology
Mainly Upper
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58[Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...](_blank)
Okete volcanics erupted from many vents,
[Geology of the Raglan-Kawhia Area: Institute of Geological & Nuclear Sciences (N.Z.), Barry Clayton Waterhouse, P. J. White 1994 ] mainly forming
greywacke
Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lit ...
, with small areas of
tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism.
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they rem ...
.
History
A study for the Regional Council said, "Harbour-wide sediment accumulation rates (SAR) have averaged 0.3-0.5 mm yr
−1 over the last 8000-6500 years. The effects of large-scale catchment deforestation (1890-1920s), conversion to pasture and plantation forestry (1985-) on sedimentation have occurred very differently in the
Waingaro
Waingaro is a rural community in the Waikato District and Waikato region of New Zealand's North Island, on the banks of the Waingaro River, where it is fed by a hot spring.
Demographics
Waingaro is in an SA1 statistical area which covers . ...
and Waitetuna arms of the harbour. In the Waitetuna arm,
14C dating of shell and exotic-pollen profiles preserved in core 12B indicate that pre-human SAR of 0.35 mm yr
−1 has increased threefold following deforestation and averaging 1.1 mm yr
−1 since 1890. Pine pollen, which is produced in large quantities and widely dispersed by the wind, suggests that SAR have further increased to 2.5 mm yr
−1 since the early 1990s. At Okete Bay (core 10B) pre-human SAR averaged 0.5 mm yr
−1. The pine pollen profile indicates that SAR have averaged 8 mm yr
−1 since the early 1990s."
A larger than average part of that post-1890 change took place when the Puketutu block, near the estuary, was bought by the Watkins Brothers in 1901. They ran a sawmill in Raglan from 1905 to 1910, largely supplied with timber floated down the river and then towed across the harbour. In 1907 Watkins were selling
kahikatea
''Dacrycarpus dacrydioides'', commonly known as kahikatea (from Māori) and white pine, is a coniferous tree endemic to New Zealand. A podocarp, it is New Zealand's tallest tree, gaining heights of 60 m and a life span of 600 years. It was fi ...
and
rimu
''Dacrydium cupressinum'', commonly known as rimu, is a large evergreen coniferous tree endemic to the forests of New Zealand. It is a member of the southern conifer group, the podocarps.
The Māori name ''rimu'' comes from the Polynesian ...
.
The deforestation took place following sale of most land in the area to settlers. The river was a boundary of the first major land sale. "On 22 March 1851, eighteen chiefs of
Ngāti-Māhanga and
Ngāti-Hourua, headed by
William Naylor, sold to Queen Victoria for the sum of £400, 19,680 acres of country bordering on the southern shores of the harbour. The western boundary of the Whāingaroa Block, as it came to be known, began at Putoetoe (the point on which the town of Raglan now stands) and followed the
Opotoru Stream inland. Leaving that stream at its junction with the Hutewai, the line ran south beyond
Te Mata to a point "marked by a hole dug by the side of the path to
Aotea." Here it turned north-eastward to run (again in a straight line) for eight miles through dense forest to meet the Waitetuna River, the last few miles of which formed the eastern boundary. The 30 square miles thus enclosed included most of the present rich farmlands lying between Karioi Mountain on the west and the Waitetuna on the east; the harbour in the north and the Wharauroa Plateau in the south. Reporting to the Colonial Secretary on 15 April 1852, after paying over the second instalment for the land, Ligar drew attention to the fact that the block was surrounded on three sides by water, thus solving to some extent the problem of communication. "The soil," he said, "is of the finest description, having for its basis a limestone formation. It is also well watered and has an abundant supply of timber for fuel, for building purposes or for commerce."
Vegetation
Pollen analysis shows that the original vegetation was kahikatea on the flats, and a mixed
podocarp
Podocarpaceae is a large family of mainly Southern Hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs.James E. Eckenwalder. 2009. ''Conifers of the World''. Portland, Oregon: Timber Pr ...
-hardwood forest on the slopes, with
totara
''Podocarpus totara'' (; from the Maori-language ; the spelling "totara" is also common in English) is a species of podocarp tree endemic to New Zealand. It grows throughout the North Island and northeastern South Island in lowland, montane and ...
,
maire,
matai, rimu,
rata,
beech
Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...
and
tree fern
The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae (scaly tree ...
s.
Kauri
''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely res ...
was present, but not abundant. From 1890 to 1930 80% of the forest was converted to pasture, though some pines have since been planted on former pasture, including by Vela Holdings east of Mangaokahu Stream in 1990–1991. By the mid-1920s indigenous forest was restricted to the steeplands of Mount
Karioi
Karioi or Mount Karioi is a 2.4 million year old extinct stratovolcano SW of Raglan in the Waikato region of New Zealand's North Island. It was the earliest of the line of 6 calcalkalic volcanoes, the largest of which is Mount Pirongia (the oth ...
,
Pirongia
Pirongia is a small town in the Waipa District of the Waikato region of New Zealand's North Island. It is 12 kilometres to the west of Te Awamutu, on the banks of the Waipā River, close to the foot of the 962 metre Mount Pirongia, which lies i ...
and the Moerangi Plateau.
Fauna and water quality
The podocarp forest is now mostly sheep and beef farms, with
Te Uku Wind Farm
Te Uku Wind Farm is a wind farm at Te Uku near Raglan, New Zealand. It has a capacity of 64MW using 28 wind turbines. Construction was completed in March 2011, at a cost of $200 million. The farm covers an area of approximately . The wind farm ...
around the sources to the south. A survey for the windfarm said, "The lower and mid reaches of the . . . Matakotea Stream provide very good native fish habitat, notably for inanga, and within well vegetated reaches, banded kokopu." It described the Waitetuna at its mouth as having moderate ecological health. A January 2008 survey identified these indicator species for stream quality as being present in the Waitetuna where it enters the harbour and in its tributary, Matakotea Stream, (the numbers on the left are the MCI Score
– the higher the score, the more sensitive these
macroinvertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate s ...
are to pollution. The words on the right show how common or rare they were in the Matakotea Stream / Waitetuna at
Te Uku
Te Uku is a small, mainly farming, settlement on SH23 in the North Island of New Zealand, located from Hamilton and from Raglan. It has a 4-Square shop, church, coffee stall and art gallery, filling station, hall, school and Xtreme Zero W ...
landing):
![Waitetuna River about 3km from the harbour](https://upload.wikimedia.org/wikipedia/commons/e/ec/Waitetuna_River_about_3km_from_the_harbour.JPG)
(9) spiny-gilled mayfly
(''
Coloburiscus humeralis'') common / -
(8) mayfly
(''
Deleatidium'') abundant / rare
(7) caddisfly (
Rhyacophilidae
The Rhyacophilidae are a family in the insect order of Trichoptera
The caddisflies, or order Trichoptera, are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can ...
) occasional / occasional
(7) dobsonfly (''
Archichauliodes diversus'')
rare / occasional
(6) riffle beetle (
Elmidae
Elmidae, commonly known as riffle beetles, is a family (biology), family of beetles in the superfamily Byrrhoidea described by John Curtis (entomologist), John Curtis in 1830. Both adults and larvae are usually aquatic, living under rocks in fas ...
) 6 common / common
(5) stony-cased caddisfly (''
Pycnocentrodes'') occasional / occasional
(5) Crustacea (''
Paratya curvirostris
''Paratya curvirostris'' is a species of freshwater shrimp in the family Atyidae. It is endemic to New Zealand, where it is distributed from North Island to Stewart Island, and including the Chatham Islands. It is the only true decapod shrimp ...
'') occasional / abundant
(4) mud snail (''
Potamopyrgus antipodarum
The New Zealand mud snail (''Potamopyrgus antipodarum'') is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae.
It is native to New Zealand, where it is found throug ...
'') abundant / abundant
(3) sand fly (''
Austrosimulium
''Austrosimulium'' is a genus of 31 species of black flies that are distributed in Australia and New Zealand. There are 2 subgenera: '' Austrosimulium'' whose species are principally from New Zealand, and '' Novaustrosimulium'' which are exclus ...
'') common / occasional
The NIWA Freshwater Fish Database shows the Waitetuna has
longfin
The longfins, also known as roundheads or spiny basslets, are a family, Plesiopidae, which were formerly placed in the order Perciformes but are now regarded as being ''incertae sedis'' in the subseries Ovalentaria in the clade Percomorpha. They ...
and
shortfin eels,
common
Common may refer to:
Places
* Common, a townland in County Tyrone, Northern Ireland
* Boston Common, a central public park in Boston, Massachusetts
* Cambridge Common, common land area in Cambridge, Massachusetts
* Clapham Common, originally com ...
and
redfin bully
The redfin bully (''Gobiomorphus huttoni'') is a species of freshwater fish in the family Eleotridae endemic to New Zealand. Being amphidromous, it spends part of its life cycle at sea. Males have distinctive bright red patterns and stripes on t ...
,
galaxiids and
inanga.
Pollution
Ministry for the Environment figures showed the Waitetuna at its mouth had 600
E. coli per 100ml (17th worst out of 154), 620
faecal coliforms per 100ml (38th of 252), 0.49 mg/litre
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
(174th of 342) and 0.04 mg/litre
phosphorus
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...
(140th of 361).
The quality is in the worst 25% of rivers for
E.coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Esche ...
, clarity,
turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality.
Fluids can ...
and worst 50% for nitrogen and phosphorus.
A government study says, "Waitetuna streams have recorded average Enterococcus counts near or above 100/100 ml, when a reading of 33/100 ml is considered the maximum safe level for contact recreation (ie, swimming). Some readings during the year reached counts of . . . 520." The river has 23 km (6.9%) of fencing, which reduces pollution by farm stock. The only comparatively good statistic on pollution is that for acidity
Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
has improved at 1.3% a year for the years 1993–2017 for nitrate-N and 3.3% for 2008–2017 for visual clarity as measured by important (i.e. slope direction probability over 95% and RSKSE over 1% pa) improvements in relative seasonal
Kendall slope estimator (RSKSE) trends (monthly records are flow-adjusted using a
Lowess curve fit with 30% span). In 2017 a farm was fined almost $50,000 for pumping dairy effluent into an area where it ponded near the river, where it could be seen from the main road. It's possible similar incidents in less public areas may account for the finding in 2011 that most pollutants in the river were deteriorating, despite fencing and planting. The study also lacked baseline data.
See also
*
List of rivers of New Zealand
This is a list of all waterways named as rivers in New Zealand.
A
* Aan River
* Acheron River (Canterbury)
* Acheron River (Marlborough)
* Ada River
* Adams River
* Ahaura River
* Ahuriri River
* Ahuroa River
* Akatarawa River
* Ākiti ...
References
External links
* 1:50,000 map http://www.topomap.co.nz/NZTopoMap/nz53407/Waitetuna-River/Waikato
Rainfall at Karamu Walkway (near source)Pollution levels
National Library 1910 photos -
Te Uku landingTe Uku bridgeMangakino Stream (joins the Waitetuna near Te Uku),3 photos
{{coord, -37.799533, 174.971645, display=title, region:NZ_type:river_source:GNS-enwiki
Rivers of Waikato
Water pollution in New Zealand
Waikato District
Rivers of New Zealand