Oamaru Borough Council public water supply race
Engineering Work (eg road, bridge, sawmill, dam)
Known locally as the Borough Race, this system was constructed to supply Oamaru with extensively reticulated potable drinking water, water for firefighting, as well as 300 ‘spare horsepower.’
It was designed by Donald McLeod (1835-?) and constructed over the three years prior to its opening 1880. Before it was completed the main water supply for Oamaru was a stream running through the town.
Water for the new system was sourced from the Waitaki River and conveyed by open race to Oamaru over a distance of nearly 50 kilometres (km). Included in the system was an intake structure, a stilling pond, 19 aqueducts and 6 tunnels, all of which meant that the scheme was extremely expensive for the local Council at £136,000.
The water was delivered to the town from an open reservoir at approximately 100 metres above sea level through a network of 600 millimetre (mm) and 450 mm cast iron pipes constructed by important Christchurch firm, Andersons. They purchased the pipes, valves and other hardware, from Alley and Maclellan - a relatively new but well respected Glasgow foundry/engineering works.
The ‘spare horsepower’ was put to very good use, powering water motors, water engines and turbines, and allowing Oamaru to be substantially hydraulically powered for decades. In 1916 the Borough Council installed an Pelton wheel driven alternating current (AC) generating plant with a 1 km wooden penstock feed off the 600mm mains. As such, Oamaru became possibly the fourth town in New Zealand to have reticulated AC and possibly the first town in the world to have reticulated AC power derived from its drinking water supply.
Notably the race functioned for 103 years and many of its components are still extant, or can be traced.
(Thanks to Bruce Comfort for these notes. To see more images of the race Click here)
Below you can listen to Bruce Comfort talking about the Oamaru Borough Council public water supply race on Radio New Zealand's Sounds Historical programme, 4 August 2013 (Part 2). The discussion begins 25:40 minutes into the programme. For ease of use, slide the scroll bar forward to this point before pressing play. (www.radionz.co.nz)
R. Aspden, ‘A surprise find – the Oamaru Water Race,’ IPENZ Engineering Heritage Newsletter, April 2010, p.4. Click here to view this newsletter
B. Comfort, ‘The Borough Race,’ 3rd Australasian Engineering Heritage Conference, Preconference Tour Information (2009)
Cyclopedia Company Limited, The Cyclopedia of New Zealand [Otago & Southland Provincial Districts], Christchurch, 1905, pp.501-02
The race runs along a range of small hills on the true right hand bank of the Waitaki River to Papakaio, where it turns "inland" and, then running parallel to the ocean edge it terminates at an open reservoir which still functions as Oamaru's town supply reservoir.
The race is clearly visible for much of its length from State Highway 83. All of the aqueducts etc. are on private land and land owner permission is therefore required to access them.
Nature of Engineering
Electrical Power Generation and Distribution, Infrastructure (incl. Road, water, ports)
(Click image to enlarge )