Philippa Stevenson: Waikato's dying lakes a money sink

COMMENT

If you want to see money being thrown down a drain there is no better place than the Waikato.

The region boasts a particular environment that's been unmatched in the world for about 17,000 years. It's also a place for sporting endeavour and scientific discovery, fun and beauty.

It is the 40-odd lakes that dot the Waikato's 60,000ha of peatland. You can't miss them even if you never go out of Hamilton or veer from the state highways.

They range from tiny Lake Cameron at Rukuhia, southwest of Hamilton, to 34sq km Lake Waikare, south of Te Kauwhata, and include Hamilton's Lake Rotoroa.

They might be lovely to look at, but getting up close and personal can be unwise. These unique environments have often become so degraded, the water so shallow and polluted, the original aquatic life dying or dead, the surrounding vegetation changed or vanished, that many have become little more than effluent drains for surrounding farms.

The deterioration is such that I asked former Waikato University bioscience senior lecturer Keith Thompson, a renowned wetland expert, whether it wouldn't be better - certainly cheaper - to just pave this paradise and put in parking lots.

Maybe only a self-styled bogman like Thompson can love a wetland, but he's certainly not ready to throw in the trowel. He is emphatic, though, that it is crunch-time for the Waikato's peat lakes.

Act now - stop tinkering round the edges of these internationally significant lakes - or we might as well bring in the concrete mixer.

But why should we value a bog?

Our peat lakes are unique and have lived so long because they are mostly dominated by tall plants - restiad rushes - instead of sphagnum moss. Overseas, the moss creeps over peat lakes and fills them in.

Nowhere else are peat lakes as ancient and nowhere else can you find the near-extinct rushes that have so far ensured their survival. It is such a rare ecosystem that it has attracted attention from the world's foremost peatland experts, including David Bellamy.

Wetlands also provide scientists with valuable information on prehistoric geology (because volcanic ash is well-preserved in lake sediment) and archaeologists with evidence and clues to a pre-European Maori way of life.

Many people enjoy the lakes, taking the chance to stroll along the shore, or to swim, kayak and sail.

But the time is long past for all 38 lakes to be saved, Thompson says.

In fact, while he told me it is now critical to make do-or-die decisions, he and others who have patiently charted the state of the lakes have been sounding similar warnings for at least 20 years.

They have been listened to - up to a point - but decisive action grows ever more urgent.

"Warm, fuzzy, feel-good wetland conservation and enhancement activities like fencing to keep out stock, planting programmes, pest-fish removal and possum control abound, but these are usually cosmetic improvements only," he says.

What most management plans lack is ways to deal with water and nutrients flowing into the lakes, and whether the wetlands can survive long-term.

In other words, all the money spent so far - $1.2 million alone by the Waipa District Council on Lake Ngaroto - could be wasted unless more and different measures are taken.

Originally, the only water flow into peat lakes was from rain or groundwater, leaving them highly acidic and with unique aquatic species. Now, nutrient-rich water from bordering farmland drains into the lakes, altering and destroying the delicate ecosystem.

Some lakes have zones that buffer them from surrounding farms - but only on a portion of the lake perimeter. It's like trying to preserve half a lake.

Thompson says the only way to save the lakes is to stop the water and nutrient inflow by creating bigger buffer zones - land that would have to be bought, which is not a cheap prospect in high-priced Waikato.

Looking less economical, though, is the high cost of fencing, planting and pest control now being undertaken at many of the lakes by district and regional councils and the Department of Conservation.

Why is money being spent at all if there is no hope of successfully turning back the clock?

If only larger buffer zones will stop more money going down the drain, then it is time to choose which lakes to save.

* Email Philippa Stevenson