Some may argue that too often rivers are treated like drains even today, but a century and a half ago, rivers were drains under this country’s law.
Under the Public Works Act 1876, “drain” was defined to include both artificial channels and “every natural watercourse, stream, and river not navigable” (s. 165). Under the Mines Act, certain rivers could be proclaimed “sludge channels”, as was the case with the Waihou and Ohinemuri Rivers in Waikato.
This may have seemed convenient at the time, especially to the country’s burgeoning mining industry, but it was not long before the consequences became too serious to be ignored. A Commission of Inquiry into the Waihou and Ohinemuri Rivers in 1910 found that these rivers had become so clogged with “sand, tailings and slime” from gold-mining operations, that it was causing the river to flood more frequently and severely, smothering the adjacent farmland with a thick layer of sediment (more than 3 inches in places). The accumulation of waste was also affecting the river’s navigability for boats.
Unsurprisingly, the Commission recommended the repeal of the proclamation and compensation for the farmers whose farmland had been most seriously affected. But of course the damage itself could not so easily be undone.
Sources: “A Natural Flow – a history of water law in New Zealand”, by Nicola Wheen, Otago Law Review (1997); Appendices to the Journals of the House of Representatives.