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Findings: Rivers, Streams, and Buffer Zones

Findings: Rivers, Streams and Buffer Zones Whilst several sections of both major and minor waterways were free from any felling, extraction or other logging related environmental impact, these areas were in the minority within all of the logged over land parcels. The Standard Logging Agreement states:
"There shall be no logging or felling of trees within 50 metres measured along the ground of any main river or water course or 25 metres of any minor water course or stream as defined on a 1:50,000 scale topographic map".
(SLA, Clause 5)

The Logging plan states further

"From experience there are streams that are not shown on the 1:50,000 maps, and in some cases those shown may not necessarily exist in the field. In these situations, where they meet the criteria, appropriate buffer strip will be established........All streams and rivers are identified well ahead prior to harvesting and roading these reserves will be marked with red paint. Monitoring of these reserves will occur during harvesting to ensure their integrity is maintained."

The worst examples of non compliance with these clauses had skid roads running upslope within the drainage channel, felling and extraction from levee banks, and indiscriminate machinery use within stream lines. Buffer strips have been extensively impacted by logging machinery, felling operations and earthworks. Debris blocking streams was also observed in almost every drainage line with a stream bed greater than 5 m wide. In some of the worst instances, major waterways were completely blocked during low flow periods by logging debris.

Contrary to the Code of Practice, most logging coupes were not marked to indicate stream buffer zones. Even in those areas where the buffer strips were marked, they were consistently utilised for machinery access and were often subjected to logging impacts.

The staff employed to mark the buffer strips were not given adequate training or equipment to delineate these buffer areas. Actual field measurements indicated that some supposedly 50 m buffer strips were in fact less than 30 m from the stream edge. Some felling actually occurred on the stream levee banks in a situation which would inevitably lead to chronic landscape instability in addition to the immediate acute impact of such operations in these inherently unstable components of the tropical lowlands.

The sediment washed into rivers and streams from poor water crossings and roads is added to by logging impacts within buffer zones. The sediment loads in waterways in the study area have resulted in eroded material being deposited upon near shore reefs and other areas normally not subjected to such impacts. The consequential losses of biota and landscape resources are clear. The streams are merely the medium transmitting unacceptable levels of artificially induced sediment loads. These factors have the potential to retard, and even deflect or prevent, natural successional processes.