Arthurs pass water (harpers pass)

The river water if fine to drink unboiled or treated. Generally hut tank water is the same but at times can get a smoky or plastic taste to it depending on fires, rainfall etc if roof collected.

Personally, I would avoid drinking from rivers with large catchments, and rivers that drain farmland or grass flats. Side creeks are likely to be clean. I probably wouldn't drink from the Taramakau or the Hurunui Rivers aside from near the pass. One other thing, watch out for didymo in the rivers and avoid transferring it to higher catchments -- I think it's in the lower Hurunui? I remember seeing it near Lake Sumner.

I've drunk water out of the upper Taramakau & Hurunui Rivers, the areas traversed by a Harper Pass trip, now & again since the mid 1970's. It has never made me ill.

John Aitken, a Christchurch-based microbiologist, did a survey of the headwaters in Arthurs Pass and the entire Waimakariri. He found no giardia in the park except from the Twin Creek near Temple Basin which is frequented by snowboarders. There was some e.coli in the tank water of the old Hawdon Hut from bird poop and the Hawdon River by the hut was cleaner to drink from but the tank water was safe. As New Zealand has no animal hosts for keeping giardia lamblia going in the back country (even deer), if introduced into the environment it will generally only be able to persist for about 18 months. Of course streams frequented by overseas folks can be a problem e.g. the Routeburn or in Abel Tasman NP. There I'd be drinking from the side streams above the track where the tourists aren't going to defecating around. Not so sure about cryptosporidium but I often see John and could ask him...

Thank you all for your replies, off tomorrow and this has been very helpful! cheers