Holiday hordes are causing more than traffic congestion in the Karangahake Gorge.

Many of the tourists who visit the area each year also pay a visit to the reserve carpark toilets, and the existing waste water treatment system is struggling to cope.

To relieve the issue, Hauraki District Council will spend around $640,000 on a new scheme to pump wastewater from the toilets to the Paeroa Waste Water Treatment system. It's expected the new scheme will be in place before next summer.

The current system, which includes a storage tank emptied by tanker, is adequate for the off season but doesn't function well during peak times.

'There's an issue with odour control and an increasing risk of overload of the onsite soakage fields, so it's important we address this problem before we have any spills,” says group manager of engineering services Adrian de Laborde.

Other solutions were investigated but the proposed scheme, which involves the installation of a small pump station at the reserve to deliver wastewater to a bigger pump station at the Karangahake Community Hall site that would then pump it to Paeroa, is the most cost-effective solution and also has the capacity to cater for some future growth in the area.

'It may seem like a lot of money to spend on one public toilet facility but you have to remember it's used by hundreds of thousands of people every year, and the numbers just keep growing” says Mayor John Tregidga.

Wastewater from existing and future commercial premises in the area, which currently have limited capacity to cope with tourism growth, and the new Karangahake Community Hall development, could also be accommodated by the new scheme.