Ashley River / Rakahuri

Ashley River / Rakahuri
Map
Native nameRakahuri (Māori)
Location
CountryNew Zealand
RegionCanterbury
Physical characteristics
SourcePuketeraki Range
 • elevation1,802 m (5,912 ft)
MouthPacific Ocean
 • location
Waikuku Beach
 • coordinates
43°16′S 172°43′E / 43.267°S 172.717°E / -43.267; 172.717
 • elevation
0 m
Length65 km (40 mi)
Basin size1,200 km2 (460 sq mi)
Basin features
Tributaries 
 • leftGlentui River, Garry River, Okuku River, Makerikeri River
 • rightLilburne River, Whistler River, Townshend River

The Ashley River (Māori: Rakahuri; officially Ashley River / Rakahuri) is in the Canterbury region of New Zealand. It flows generally southeastwards for 65 kilometres (40 mi) before entering the Pacific Ocean at Waikuku Beach, Pegasus Bay north of Christchurch. The town of Rangiora is close to the south bank of the Ashley River. The river's official name was changed from Ashley River to the dual name Ashley River / Rakahuri by the Ngāi Tahu Claims Settlement Act 1998.[1]

Though the lower reaches of the river are braided, part of the upper river flows through a canyon known as the Ashley Gorge.

The river emanates from mountains in the west Lees Valley adjacent to Island Hills station and exits the hills at a gorge near Oxford township. It has tributaries of Duck Creek in this valley and is an accumulator of watershed between Lees Valley and Oxford township.

Behind Waikuku Beach is one of the largest, least modified estuaries in New Zealand. It is abundant in bird life, including the wrybill (Anarhynchus frontalis) and Black stilt (Himantopus novaezelandiae). Many migratory birds over-winter here. Surveys from 2000 to 2015, after work to clear weeds and pests, showed significant increases in banded dotterel, wrybill, black-fronted tern, and pied stilt, but black-billed gull, spur-winged plover and southern black-backed gull didn't change significantly.[2]

Floods

In February 1868, June 1905 and May 1923 flooding from this river extended as far as Kaiapoi. Major floods also occurred in March 1902, February 1936, March 1941, February 1945, January 1953, December 1993 and 2013. 34.7 km (21.6 mi) of stopbanks have been built from the 1930s and have contained the floods since 1953, being enlarged in 1976 and 2018. On the north bank they extend from the railway bridge to the coast and on the south bank to Mount Thomas Road.[3]

Bridges

Cones Road Bridge

Cones Road Bridge from south in 2019

The Cones Road Bridge is located at 43°16′56″S 172°35′07″E / 43.2822°S 172.5854°E / -43.2822; 172.5854 and connects Rangiora to Ashley and Loburn. It is a 10-span, 300 m (980 ft) long bridge, opened in 2015,[4] replacing a 24-span, 1912 bridge, after closure by floods in 2013. It is built of hollow-core concrete beams and has 2 road lanes, 2 cycleways and a footpath. The original bridge was built in 1897.[5]

Railway Bridge from south in 2021

Railway Bridge

The bridge opened with the Rangiora to Ashley section of the Northern Railway on 17 April 1875.[6] It was 3,055 ft (931 m) long and built of timber, with 54 spans.[7] In April 1951 a pier and two iron girders were washed away in a flood.[8] It was replaced by a 549 m (1,801 ft) bridge to the east on 18 December 1961.[9]

Main North Road Bridge

The first bridge was completed in 1866.[10] It was initially a toll bridge, but by 1867 had been bought by the Provincial Council.[11] After floods, it was lengthened in 1868.[12] It was rebuilt 10 ch (660 ft; 200 m) downstream and 1,190 ft (360 m) long by 22 ft (6.7 m) wide, on 25 reinforced concrete spans,[13] opening in August 1937,[14] after flood damage in 1936.[15] Floods had also closed it in 1870,[16] It is now part of State Highway 1 and was repaired and strengthened in 2019.[17]

References

  1. ^ "Ngāi Tahu Claims Settlement Act 1998 (1998 No 97)".
  2. ^ "Population trends of braided river birds on the Ashley River (Rakahuri), Canterbury, New Zealand, 1963–2015" (PDF). Ornithological Society of New Zealand. Archived (PDF) from the original on 28 February 2018.
  3. ^ "Ashley River floodplain investigation – 2016 update".
  4. ^ "Ashley River Bridge Replacement". Concrete Structures (NZ) Ltd. 23 August 2019. Retrieved 2 April 2021.
  5. ^ "Core benefits Ashley River bridge". Contractor Magazine. 9 November 2014. Archived from the original on 8 February 2020. Retrieved 2 April 2021.
  6. ^ "OPENING OF THE NORTHERN RAIL WAY TO ASHLEY TOWNSHIP. STAR (CHRISTCHURCH)". paperspast.natlib.govt.nz. 19 April 1875. Retrieved 2 April 2021.
  7. ^ "ASHLEY RAILWAY BRIDGE. PRESS". paperspast.natlib.govt.nz. 27 March 1873. Retrieved 2 April 2021.
  8. ^ "April 1951 Canterbury Flooding". hwe.niwa.co.nz. Retrieved 3 April 2021.
  9. ^ New Zealand Railway and Tramway Atlas (First ed.). Quail Map Co. 1965. pp. 3 & 4.
  10. ^ "PRESS". paperspast.natlib.govt.nz. 13 June 1866. Retrieved 2 April 2021.
  11. ^ "PROVINCIAL COUNCIL. PRESS". paperspast.natlib.govt.nz. 29 December 1866. Retrieved 2 April 2021.
  12. ^ "Local and General. STAR (CHRISTCHURCH)". paperspast.natlib.govt.nz. 12 October 1868. Retrieved 3 April 2021.
  13. ^ "ASHLEY RIVER BRIDGE. PRESS". paperspast.natlib.govt.nz. 30 May 1936. Retrieved 3 April 2021.
  14. ^ "BRIDGE NOW OPEN. NORTH CANTERBURY GAZETTE". paperspast.natlib.govt.nz. 20 August 1937. Retrieved 3 April 2021.
  15. ^ "THE NEW ASHLEY RIVER BRIDGE VIEWED FROM THE AlR. Press". paperspast.natlib.govt.nz. 30 September 1937. Retrieved 2 April 2021.
  16. ^ "Local and General. STAR (CHRISTCHURCH)". paperspast.natlib.govt.nz. 29 August 1870. Retrieved 3 April 2021.
  17. ^ "Ashley River/Rakahuri Bridge, North Canterbury, SH1 – night closures coming up". nzta.govt.nz. Retrieved 3 April 2021.

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