The Waikato peat lakes form the largest collection of peat lake habitat in New Zealand. They represent some of the few remaining areas of wetland once part of the formerly extensive Komakorau, Rukuhia and Moanatuatua peat bogs.
Peat forms from the build up of partially rotted plant material in wet environments. Peat lakes form in peatland areas such as bogs. Peat soils have a marked effect on the physical, chemical and biological nature of peat lakes. For example, the water is usually stained a brownish colour due to the high levels of dissolved organic matter leaching from adjoining peat soils. Water in the bottom of the lake is usually mildly acidic and often low in dissolved oxygen.
Peat lakes have unique plants and animals that have evolved to cope with their acidic conditions. Changes in water quality due to the surrounding land use could threaten these specialised plants and animals.
Lake Ngaroto is the largest of the Waipa peat lakes. The lake catchment is mainly pastoral. The lake has a surface area of about 108 hectares. It has a maximum depth of four metres and an average depth of less than two metres. Over the past 150 years, the lake level has been lowered, and much of the surrounding area drained for pasture. Today, the lake and fringe wetlands occupy less than half of the original wetland area. The water is of poor quality due to high nutrient input, leading to algal blooms and sedimentation.
Waipa District Council started a restoration project in 1995, creating marginal strips of land around the lake that could be fenced and planted. The whole lake boundary is now fenced and well over half of the lake edge is planted. Considerable effort has been made to plant native species grown from locally sourced seed.
Newly planted native species will encourage more wildlife (including native birds) back to the area. The lake is also used for recreation, and the boardwalk built by Te Awamutu Kiwanis Club greatly enhances access to and around the lake.
The restoration project received a wetlands conservation award from the Minister of Conservation in February 2000, and was nominated for a Ministry for the Environment Green Ribbon Award in 2002.
The cache is a camo'd pill bottle.