Living in the Rain Shadow.

Wind roars across the southern oceans west to east bearing vast amounts of moisture.  Then smashes into the west side of our mountains, the 'Southern Alps". dumping a lot of rain in a very small area. That leaves a dry 'rain shadow' to the eastern side.   The difference  is remarkable.  Over just 60-80 kilometers, a saturated rain forest changes to bone dry desert like land.

The same effect occurs in southern Chile, which has rainforest as the weather dumps on the western side of the southern Andes mountains.  The eastern side of the Andes are dry, forming the magnificent and distinctive landscapes of Patagonia, southern Argentina.

For a more scientific explanation try this link to Wikipeadia which says in part - On the South Island of New Zealand is to be found one of the most remarkable rain shadows anywhere on Earth.  

It's dry in the 'rain shadow' but huge rivers flow out of the mountains and across the dry places.  Here the Kawarau river flows out of it's gorge past the back gate of "The Field of Gold".  It's no small river with an average flow of 218 Cumecs (Cubic Meters per Second).

The 'Field of Gold' is on the right of the river as it flows out of the gorge.  Near the white Cherry nets.

Living in the rain shadow means we also have bright sunny days most of the time.  Here at Bannockburn we have the driest place in New Zealand which would usually make it hard to grow things.  But we have access to vast amounts of water.

But it's not like the United States where 25 million people rely on equivalent rivers like the Colorado with no alternative.  Here fewer people than 50,000 people rely on the local rivers, the Kawarau, the bigger Clutha, and their huge cousin the Waitaki river, just over the hill.

A few years ago this was dry barren rocky land.  Now vineyards.  Because of the application of water.

This photo joins the one above.  Lake Dunstan, fed by two major rivers.  The Kawarau and the Clutha.

There were some storms and floods in the mountains, not that we knew much about it as the rain did not reach us in any quantity.  In the news we saw a rare event, the Benmore Dam on the Waitaki was spilling.  A rare event which only happens about once a year.

So we had a day out.  Up over and down the Lindis pass about 150 Kilometers.

It was spectacular.

This dam is huge.  That's a couple of Kilometers away.  ( more than a mile)

Disturbing at a distance. Scary up close.

There were certainly a lot of people there.  Many had come hundreds of kilometers to the middle of the nowhere to see this.

The Waitaki river averages about 340 cumecs.  Running in these photos at about 1200 cumecs although a lot of that is going through the power turbines and not down the spillway.  The spillway can handle 3400 cumecs.  The day that happens I am not coming anywhere near the frightening thing.