The Middle Waikato Management Zone covers an area of 174,451 ha. The zone represents 12 percent of the total project catchment area. The boundaries of the zone are shown in map 2. Of the total area, 68 percent is in pasture, 21 percent in production forestry, and six percent in native vegetation, scrub and other land uses
The predominant geology of the area is volcanic material, including tephra which accounts for 65 percent. Twenty six percent is made up of alluvial and unconsolidated sediments. Taupo pumice makes up four percent, peat three percent and greywacke or argillite two percent.
The Karapiro Catchment Control Scheme is included in the zone. This catchment scheme is in the vicinity of Lakes Karapiro and Arapuni, and located in the middle reaches of the Waikato River system. The primary objectives are to protect the land draining to these lakes from soil erosion and therefore enhance lake water quality. Works include retirement of erosion prone lakeshore land, conservation planting and erosion control structures.
The zone also includes the most significant urban areas in the catchment including Hamilton City, Cambridge, Tokoroa, Tirau, Putaruru and Ngaruawahia.