In the past, we've concentrated on controlling "point sources" of water pollution - discharges of waste that come from an identifiable source, such as the end of a pipe.

Now attention is being focused on "non-point" pollution sources, which are much more diffuse, but which can cause microbiological contamination of waterways, sedimentation and algal growths that smother aquatic habitat, and contamination by hazardous substances.

Such impacts are of greatest concern in the region's small rivers, lowlands lakes, unconfined groundwater zones, and water bodies that receive high human use.

The Cause

Sediment from soil erosion, bacteria from grazed land and chemical contamination from leaks and spills and inappropriate use and disposal of chemicals all pose a hazard to the health of aquatic life and to the safe use of water for human or stock consumption.

The increase in dairying in mid and south Canterbury increases the chances of contamination of streams and groundwater, especially where it is combined with border dyke irrigation.

The Options

Provide information on causes of non-point pollution and ways to avoid or reduce it through actions like sediment and nutrient control and maintenance of good streamside vegetation.

This leads to better community awareness, but any action is purely voluntary.
Encourage community groups to "adopt" degraded water bodies that have high community values, such as for recreation, and work with landholders to implement appropriate management measures.

Involving the local community in management is a positive step, but again it is purely voluntary.
Carry out targeted investigations in priority management areas to develop a more detailed understanding of non-point pollution, identifying contaminant sources and critical management factors.

This gives us a sound basis for targeted management in the future, but the cost of the investigation would be borne by the ratepayer.
Encourage and support the preparation of property plans identifying site specific management practices to avoid or manage non-point pollution.

This is a focused and integrated approach, but it is not enforceable and plans may cover only part of a polluted area.
Prepare regional rules to control potentially high impact land use activities, with the greatest control in priority management areas. An example is controlling pesticide use or effluent spreading in areas around wells or near to lakes or streams.

This is a proactive approach which offers certainty of action, but compliance with rules may be difficult to monitor.
Offer incentives for preparation and implementation of site specific management plans, such as cost sharing for fencing, planting materials and provision of alternatives stock water supply.

Incentives encourage action, but can be expensive for regional ratepayers.
Require financial contributions as part of resource consents for high risk activities to fund mitigation of remedial measures.

This would provide an opportunity to address the problem, but tying it to resource consents limits its use.