Integrated Catchment Management

Tall vegetation effects on water yield

 Research Status: Ongoing
A mixed land use catchment with tall vegetation in the headwaters

A mixed land use catchment with tall vegetation in the headwaters


A decision support system (DSS) has been developed to assist land managers in assessing possible changes in water yield from a catchment with a change in vegetation cover. The DSS consists of compiled background information on water use by different vegetation covers in New Zealand, and a simple-to-use computer model (WATYIELD) that simulates water yield changes following a change in vegetation cover. The project has been supported by the Sustainable Management Fund (SMF) from the Ministry for the Environment and also 6 regional and city councils in New Zealand.

Research Approach

Five reports have been compiled that details aspects of water quantity and land use change. The reports are a synthesis of knowledge up until 2004.

A simple-to-use computer model (WATYIELD) has been developed to simulate the effects of land cover change on water yields in small to moderate catchments.

WATYIELD is available for a free download. There is also a user manual available for download. Note: the model was updated in 2009 and the new downloadable zip file is available. (see More details below to access the reports and model).

Research Results

The 7 publications produced from the project are listed below (search main database by date to download reports):

Further research has been in the area of how forestry affects low flows and general flows. This has concentrated on taking available data and applying it through the WATYIELD model to investigate land use change implications

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Recent Publications

Year Title File Size
2012 A Summary of Outcomes and selected formal publications from the Integrated Catchment Management (ICM)research programme:2000 – 2011
pdf       1.08MB
2010 Runoff generating processes in adjacent tussock grassland and pine
plantation catchments as indicated by mean transit time estimation
using tritium
pdf       2.16MB
2008 Fundamentals of Hydrology (2nd edition) pdf       507KB
2007 Flood regime of a pumice catchment pdf       337KB
2006 Forests for soil and water conservation – what does the science say? pdf       112KB
2006 Tussock grasslands and high water yield: a review of the evidence. pdf       199KB
More publications on this topic »
All ICM Publications »

Recent Presentations

Year Title File Size
2007 Forest Hydrology Processes pdf       2283KB
2006 Afforestation and water yield: the New Zealand experience. pdf       452KB
2002 A Decision Support Tool for Assessing the Effects of Land Cover Change on Water Resources. pdf       393KB
More presentations on this topic »
All ICM presentations »

BMPs, BEPs and Guidelines

Title Description
New Zealand Environmental Code of Practice for Plantation Forestry The E CoP is an essential tool for anyone involved in forest management. Developed by the NZFOA, and...More »  
All BMPs, BEPs & Guidelines »

Primary Contacts:

Image - Tim Davie Tim Davie  EmailSend email to tim.davie
Phone: 03 372 7084
Fax: +64 (0)3 365 3194
More details»
Environment Canterbury
Hydrology & modelling, surface water resource management
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Page last updated Friday, 26 March 2010

Related areas

Forest harvesting effects Mechanisms of groundwater recharge Upper Motueka water resources