The Coldwater River is in south central British Columbia, Canada.[2] The river is the largest tributary of the Nicola River, which is joined at Merritt.
Name origin
Tsillatko (or alternative spellings), the Shuswap name for the river, translates to "cold water".[2][3] The earliest known documented use of the Coldwater River name is 1875.[4] G.M. Dawson's Southern Interior of B.C. map (1877) is the earliest map adopting this name.[5]
Course and environment
From west of the Coquihalla Lakes[6] on the northeastern slopes of the North Cascades, the river flows northeastward, before entering the Nicola at Merritt.[7] The length is about 94 kilometres (58 mi) and channel width is 10 to 25 metres (33 to 82 ft).[8] Water temperature does not rise above 10 °C (50 °F) until early July, whereas in the Nicola, water exceeds that by early June.[9] The average gradient of the lower 90 kilometres (56 mi) is 0.6 per cent. The watershed area covers 915 square kilometres (226,000 acres).[10] Annual precipitation in the upper watershed is 1,000 millimetres (39 in) and at Merritt is 255 millimetres (10 in).[7]
The watershed is snow dominated with summer low flows occurring late August–September and late winter. Commercial and industrial land use, which is primarily in Merritt, impacts about 1.0 per cent on both banks of the river. Upstream, agricultural land use occupies 3.7 per cent of both banks. Rural land use occurs along about 11.2 per cent of the left bank, and 23 per cent of the right bank. Infrastructure accounts for about 3.2 per cent and 4.4 per cent of the left and right banks respectively, which is largely a result of the 24 bridges along the river.[11]
Along the cobble-bedded, irregularly meandering river, abandoned channels have created low-lying areas of wetland. Valley walls are primarily formed of till overlying bedrock.[12] The installation of revetments over the past century has restricted the meandering.[13] The river passes through two biogeoclimatic zones. In the upper reaches, it passes through the Interior Douglas Fir Zone. On entering the Coldwater Valley bottom, the region changes to the drier Ponderosa Pine/Bunch Grass Zone.[7] The route includes the Coldwater River Park (near Juliet)[10] and only one canyon (7-kilometre (4 mi) length, north of Brodie).[14]
Discharge
Daily discharge tables for the Coldwater River at:
Brook Creek mouth for 1965–2022.[15]
Merritt for 1913–2022.[16]
Nlaka'pamuxFirst Nations have inhabited the Coldwater valley at least since the early 1800s.[26] The main reserve of the Coldwater Band is Coldwater 1. Paul's Basin IR 2 is southwest of IR 1 and Gwen Lake 3 is on Gwen Lake, which feeds Kwinshatin Creek.[27][28]
Developed during 1872–1876, a 2-metre (6 ft) wide upgraded cattle trail, which connected Hope and Merritt via the Coquihalla Pass, was destroyed in the 1910s by the Kettle Valley Railway (KV) construction.[30]
In 1910, a new wagon road was built along the Voght Valley,[31] which included the corresponding part along the east shore of the Coldwater from Merritt.[32]
By 1931, a minor road headed westward to Brookmere.[33]
By 1956, the road along the east shore had been extended to Brookmere.[34]
In 1960, Trans Mountain Pipeline bought the Brodie–Jessica right-of-way.[35] and built a private road north from Portia largely upon the former rail bed.[30] In summer 1963, a passenger vehicle convoy made a promotional public use of the Brookmere–Portia route, which comprised the private pipeline road and logging roads.[36] The tenth such annual excursion in 1973 appears to have been the last.[37] By the mid-1970s, the public use of this road was increasing.[38] Consequently, petitioning for the long promised highway intensified.[39]
In May 1985, a tanker spilled about 500 litres (110 imp gal; 132 US gal) of diesel fuel, which flowed into the river. The respective Coquihalla Highway contractor was later acquitted on a charge of negligence.[40] By that summer, the public could use the highway while earthmovers developed the grade.[41] Opened in May 1986, the highway parallels the river for almost 39 kilometres (24 mi). Construction required six bridges and three river diversions. The lower reaches of Juliet and Mine creeks were also impacted. The Ministry of Transportation and Highways installed several compensating river channels for spawning.[42]
Pipelines
In 1953, the Trans Mountain Oil Pipe Line was installed along the river.[43] In 1955, a pipeline easement through the reserve was granted to Trans-Mountain Oil Pipeline Ltd.[26]
The Westcoast Pipeline, which carries natural gas, was completed through the Coldwater and Coquihalla valleys in 1957 and expanded in 1979.[44]
In April 1971, a washout left 61 metres (200 ft) of pipeline suspended. On fracturing, the pipe leaked crude oil, which was contained behind a quickly prepared earth dam. During repairs, the greater part of the 950,000 litres; 250,000 US gallons (210,000 imp gal) of released oil entered the dam, but none reached the river.[45] Over the decades, the pipeline companies modified extensive sections of the Coldwater River to protect the buried pipe from river scour.[46]
The Trans Mountain Expansion Project route was revised in 2021 when the Coldwater Band claimed that the original proposal might potentially damage the reserve aquifer. The change added about 4 kilometres (2 mi), necessitated two crossings of the Coldwater River where none were needed before, and raised further concerns about the local environmental impact.[47] By February 2024, the project was almost complete along the river between Merritt and the Coquihalla Summit.[48]
Flooding
During May–June 1948, the rising river at the Collettsville Bridge flooded residences.[49]
In February 1962, a blockage from broken ice caused the river to flood basements.[50]
In late December 1980, the largest recorded floods to that time changed the river channel morphology, which prompted revisions of the draft study examining the expected impact upon the river of the proposed Coquihalla Highway.[51] The flooding caused extensive damage to roads and bridges and the loss of farmland.[52]
The river flooded parts of Merritt due to very high water in 1995[53] and an ice jam in 2005.[54]
During the 2021 Pacific Northwest floods, the river damaged the Merritt wastewater treatment plant, about 600 residences, and several commercial properties. The entire community of 7,100 residents had to be evacuated.[55] Upstream, workers were able to save the highway bridge at Brodie by dumping rock to protect an abutment.[56] Along a 30-kilometre (19 mi) stretch south of Merritt, the 14 exposed sections of the existing oil pipeline cost tens of millions of dollars to repair[57] and route revisions were required for the expansion project where river channels had altered.[58]
Overpass of Voight Creek and Coldwater Rd: 46-metre (150 ft) timber frame trestle. Replaced by 20-metre (65 ft) steel deck plate girder span likely in 1941. Removed in spring 1999.
^a . Mileages are 1931–1961, measured from the Spences Bridge Station building.[86] ^b . Unless specified otherwise, infrastructure detail is c.1931. ^c . Section house erected southeast side of main line. ^d . E.G. Walker was the owner of a nearby ranch.[87]. ^e . Nicola Pine Mills operated a logging railway 1920–c.1926, which crossed the river south of Midday Creek, before going northwestward along the creek about 10 kilometres (6 mi). Logs were loaded onto the KV at Pine. ^f . Thirteen miles was likely the approximate pack trail or wagon road distance from Merritt.
KV infrastructure and incidents for Kingsvale–Brodie
In 1930, when a striking a boulder derailed a westbound locomotive and two loaded coal cars, the locomotive slid down an embankment and the fireman died.
^a . Mileages are 1931–1961, measured from the Spences Bridge Station building.[86] ^b . Unless specified otherwise, infrastructure detail is c.1931. ^c . Station, section house, and water tank, erected west side of main line. ^d . Delbert (Dell) King was a local rancher,[87] who owned the surrounding land, but his aspirations for a major settlement never transpired.[90]
Coldwater River: 30-metre (100 ft) east–west Howe truss with pile trestle approaches, which were filled 1925. Replaced by 33-metre (108 ft) steel deck lattice truss in 1931. Removed in 2000.
Coldwater River: 30-metre (100 ft) north–south Howe truss. Replaced by 30-metre (100 ft) steel through plate girder span in 1932. Removed following Nov 2021 floods.
In Oct 1913, five loaded dump cars broke loose and ran down the grade toward Merritt. The engineer of an ascending locomotive engaged reverse and gained sufficient speed for the dump cars to gently contact and be brought under control.
In Mar 1930, when a westbound freight train hit a rockslide, the locomotive derailed and the fireman died. In the early 1980s, the Highway 5 construction obliterated the railway right-of-way from the station to here, before reappearing west of the highway.
^a . Mileages are 1940–1961, measured from the Brookmere Station building.[99] ^b . Unless specified otherwise, infrastructure detail is c.1931. ^c . Section house erected on the north side of the river, inside the loop. ^d . Called Mons Junction prior to summer 1915 rename. ^e . Tails of wye: north to Merritt, south to Coquihalla, and east to Brookmere. Used mainly for turning locomotives, but also provided direct access for trains diverted via Merritt.[98]
KV infrastructure and incidents for Juliet–Coquihalla
Juliet Creek: 32-metre (106 ft) steel through plate girder span, which now provides road access to Coldwater River Provincial Park. Immediately north of Exit 228, the bridge is now part of Coquihalla Lakes Road, which largely follows the right-of-way to Mile 19.6
^a . Mileages are 1940–1961, measured from the Brookmere Station building.[99] ^b . Unless specified otherwise, infrastructure detail is c.1931. ^c . Section house and water tank erected southeast side of main line. ^d . During the mid-1920s, a log flume descended to the passing track.