05 Sep Reece Hill
Reece Hill, New Zealand
Dr Reece Hill is the Senior Soil Scientist at the Waikato Regional Council, New Zealand and the Immediate Past President of the New Zealand Society of Soil Science. Dr Hill trained in pedology and soil stratigraphy and has worked at council for 15 years. Over that period he has implemented monitoring programmes for soil conservation, soil quality, riparian characteristics and land use change, providing guidance on these nationally. Dr Hill also convenes a forum of regional council soil scientists developing consistent methods for land and soil monitoring in New Zealand.
Presentation Title: Prioritising soil conservation and water quality issues for the Waikato River and Waipa River Restoration Strategy, New Zealand.
The Waikato Regional Council, Waikato River Authority and Dairy NZ recently developed the Waikato River and Waipa River Restoration Strategy, which includes a 15-20 year Action Plan for the restoration and protection of these rivers in the Waikato region, New Zealand. The Strategy will ensure restoration activities are appropriate, coordinated, effective and efficient for implementing non-regulatory soil conservation throughout the restoration catchment which covers an area of about 1.3 million hectares. This paper outlines the main methods used to identify and prioritise soil conservation and water quality issues, estimate the costs for implementing soil conservation mitigations, and estimate the sediment reduction benefits for implemented soil conservation mitigations. A spatial (Geographic Information System – GIS) based framework to prioritise soil conservation and water quality issues has been developed using available model outputs and regional datasets (including erosion, sediment generation, diffuse nutrients and bacteria generation). Data were imposed on a spatial hydrological dataset and sub-catchment data generated to identify the location and relative intensity of issues for selected soil conservation and water quality related factors (e.g. sediment, nutrients and erosion). The approach, primarily a desktop analysis, was checked for “real world” representation with land managers. The outputs (maps and data) provided an effective means of conveying the issues and catchment priorities in an approachable way. Workshops with land managers identified realistic soil conservation mitigations, effective placement in the landscape and costs. Soil conservation mitigations were imposed onto existing model data in the GIS framework and cost data provided for all sub-catchments. Sediment reduction values were attributed to soil conservation mitigations and imposed onto sediment model data in the GIS framework to estimate the sediment reduction benefits for all sub-catchments. This information proved essential when deciding the relative cost: benefits ratio of sub-catchment scale soil conservation and prioritising projects within the Restoration Strategy.