Soil Stability and Disturbance in the Kawhia Catchment - Changes from 2002 to 2007

Report: TR 2010/25
Author: A B Thompson (Thelton Environmental Ltd) and D L Hicks

Abstract

 The Waikato Regional Council has requested an assessment of the extent of erosion, and coverage by soil conservation measures in a catchment that is representative of the region’s west coast management zone. This zone encompasses all catchments west of the Waikato and Waipa watersheds.   The assessment is intended to assist with upcoming discussions with the community as to the future promotion of catchment protection programmes in the zone.

The Waikato Regional Council contracted Mr. A.B. Thompson (Thelton Environmental) to undertake the assessment, with involvement of Dr. D. Hicks as needed for analysis procedure and comparisons.   Following discussion with Waikato Regional Council staff, Kawhia was selected as a representative catchment.   The assessment was undertaken as a point sample from aerial photographs. This is now a standard method for assessing erosion and erosion control measures, used by EW as well as other regional councils.

The report starts with an overview of soil stability, soil disturbance and bare soil.   It then gives results from the 2007 assessment of soil conservation measures for Kawhia, and compares them with results from a previous assessment in 2002. Results and comparisons are split according to whether land is farmed, planted in forest, or under natural vegetation, then grouped as a single catchment-wide summary.

Soil Stability and Disturbance in the Kawhia Catchment - Changes from 2002 to 2007 [PDF, 146 KB]