Anthropic Soil. In most instances requirements under the
Resource Management Act (1991) to ‘avoid, remedy, or
mitigate, adverse effects on the environment’ ensure that
land restoration, and reconstruction of a viable soil, and
revegetation are undertaken.
There has been a long history of peat mining in the
Waikato with peat mined, for potting mix and mushroom
growing, on the Hauraki Plains. For example, one company
had a ‘coal mining’ licence for an area of about 60 ha of peat
and has been required to pay tens of thousands of dollars in
bonds to ensure appropriate rehabilitation works are completed following the mining activity.
Growing ‘instant lawn’ is also a form of soil mining and
export. The removal of a thin topsoil layer would not meet
the Anthropic Soils requirement of a ‘drastic’ change from
the original soil. However, repeated removal, to the degree
that the soil resource is depleted (and its diagnostic horizons
and features are lost, or eventually fail the necessary thickness criteria), may lead to a remaining soil that should be
classified as a Truncated Anthropic Soil.
Clay materials are mined at a number of sites in New
Zealand including halloysite at Matauri Bay in Northland for
fine china clay, ‘fire clay’ at Huntly for brick making,
Waikari and Patumahoe clays for cricket pitch construction,
and bentonite on the Hawke’s Bay coast at Porangahau for
drill lubricant, ‘kitty litter’, and an increasing number of
health and beauty products.
3.3.5 Soil Relocation from Cromwell Gorge
The Clyde hydroelectric dam in Central Otago was built as
part of the government development ‘Think Big’ strategy in
the early 1980s. The dam flooded the valley of the Cromwell
Gorge and part of the upper Clutha valley upstream of
Cromwell town. The Cromwell Gorge was a particularly
important area for stone fruit production. The area had deep,
high water-holding capacity, silty, soils and was subject to
down-river cold air drainage that reduced the risk of frost
damage to developing fruit. Amid much controversy, a
suggestion was made that the silty water-retentive soil
material should be relocated onto river terraces that would
not be flooded by the dam. At the relocation site, the soils
were stony with poor water-holding capacity and would
clearly benefit from addition of the relocated soil. A crop trial
was initiated by Gary Beecroft and Don Brash to estimate the
expected gain in fruit production. However, soil relocation
was never undertaken due to the perceived costs. Perhaps in
the twenty-first century, with stronger legislation requiring
people to avoid, remedy, or mitigate adverse effects of
development, soil relocation could become a viable option.
3.3.6 Urban Anthropic Soils
Urban soils were first recognised internationally in large,
long established, cities that have been repeatedly rebuilt on
top of previous habitation. Archaeologists have used
deposits of human artefacts for historical interpretation. In
New Zealand where soil disturbance is being undertaken for
urban construction it is important to be alert to any artefacts
that may be uncovered and protocols need to be in place at
construction sites to consult local iwi and archaeological
authorities should any artefacts be identified.
Since implementation of the Resource Management Act
in 1991, any development that involves earth moving
requires resource consent. As a result, a lot of effort and
detailed engineering design goes into planning all major
earthworks to ensure a sustainable outcome and to prevent
adverse effects on the environment. Effects are monitored
and managed both during the construction process, and
following completion of the development. For example, all
storm-water runoff must be contained and treated before
discharge to prevent sediment runoff during construction.
Designs must also provide for ongoing treatment and
attenuation of storm-water runoff once a development is
completed.
Urban Anthropic Soils may be designed, and natural soils
may be included in development plans, to achieve multiple
landscape aesthetic, productivity, hydrological, environmental, and engineering goals. Features of urban designs
may include:
• use of permeable surfaces, rather than sealed surfaces, to
slow and reduce the amount of runoff,
• ‘rain gardens’ where water can pond then slowly infiltrate
to decrease runoff,
• light-weight soils for living roofs,
• provision of areas with sufficient soil root volume to
support large trees within paved areas such as carparks
and footpaths,
• re-use of soil displaced by buildings and road construction, and
• designed sites for placement of ‘waste materials’, both
inert fill materials and modern landfills.
Where urban development is designed to utilise the natural land surface (without major recontouring), it is useful to
understand the original soils and landscape so that the
development can be designed to best fit the site and soil
properties. For example, the existence of naturally deep
permeable, soils can save the construction of costly drainage,
runoff, and irrigation works. Urban development without
recontouring is mainly used in lower density developments.
46
3 Anthropic Soils
Resource Management Act (1991) to ‘avoid, remedy, or
mitigate, adverse effects on the environment’ ensure that
land restoration, and reconstruction of a viable soil, and
revegetation are undertaken.
There has been a long history of peat mining in the
Waikato with peat mined, for potting mix and mushroom
growing, on the Hauraki Plains. For example, one company
had a ‘coal mining’ licence for an area of about 60 ha of peat
and has been required to pay tens of thousands of dollars in
bonds to ensure appropriate rehabilitation works are completed following the mining activity.
Growing ‘instant lawn’ is also a form of soil mining and
export. The removal of a thin topsoil layer would not meet
the Anthropic Soils requirement of a ‘drastic’ change from
the original soil. However, repeated removal, to the degree
that the soil resource is depleted (and its diagnostic horizons
and features are lost, or eventually fail the necessary thickness criteria), may lead to a remaining soil that should be
classified as a Truncated Anthropic Soil.
Clay materials are mined at a number of sites in New
Zealand including halloysite at Matauri Bay in Northland for
fine china clay, ‘fire clay’ at Huntly for brick making,
Waikari and Patumahoe clays for cricket pitch construction,
and bentonite on the Hawke’s Bay coast at Porangahau for
drill lubricant, ‘kitty litter’, and an increasing number of
health and beauty products.
3.3.5 Soil Relocation from Cromwell Gorge
The Clyde hydroelectric dam in Central Otago was built as
part of the government development ‘Think Big’ strategy in
the early 1980s. The dam flooded the valley of the Cromwell
Gorge and part of the upper Clutha valley upstream of
Cromwell town. The Cromwell Gorge was a particularly
important area for stone fruit production. The area had deep,
high water-holding capacity, silty, soils and was subject to
down-river cold air drainage that reduced the risk of frost
damage to developing fruit. Amid much controversy, a
suggestion was made that the silty water-retentive soil
material should be relocated onto river terraces that would
not be flooded by the dam. At the relocation site, the soils
were stony with poor water-holding capacity and would
clearly benefit from addition of the relocated soil. A crop trial
was initiated by Gary Beecroft and Don Brash to estimate the
expected gain in fruit production. However, soil relocation
was never undertaken due to the perceived costs. Perhaps in
the twenty-first century, with stronger legislation requiring
people to avoid, remedy, or mitigate adverse effects of
development, soil relocation could become a viable option.
3.3.6 Urban Anthropic Soils
Urban soils were first recognised internationally in large,
long established, cities that have been repeatedly rebuilt on
top of previous habitation. Archaeologists have used
deposits of human artefacts for historical interpretation. In
New Zealand where soil disturbance is being undertaken for
urban construction it is important to be alert to any artefacts
that may be uncovered and protocols need to be in place at
construction sites to consult local iwi and archaeological
authorities should any artefacts be identified.
Since implementation of the Resource Management Act
in 1991, any development that involves earth moving
requires resource consent. As a result, a lot of effort and
detailed engineering design goes into planning all major
earthworks to ensure a sustainable outcome and to prevent
adverse effects on the environment. Effects are monitored
and managed both during the construction process, and
following completion of the development. For example, all
storm-water runoff must be contained and treated before
discharge to prevent sediment runoff during construction.
Designs must also provide for ongoing treatment and
attenuation of storm-water runoff once a development is
completed.
Urban Anthropic Soils may be designed, and natural soils
may be included in development plans, to achieve multiple
landscape aesthetic, productivity, hydrological, environmental, and engineering goals. Features of urban designs
may include:
• use of permeable surfaces, rather than sealed surfaces, to
slow and reduce the amount of runoff,
• ‘rain gardens’ where water can pond then slowly infiltrate
to decrease runoff,
• light-weight soils for living roofs,
• provision of areas with sufficient soil root volume to
support large trees within paved areas such as carparks
and footpaths,
• re-use of soil displaced by buildings and road construction, and
• designed sites for placement of ‘waste materials’, both
inert fill materials and modern landfills.
Where urban development is designed to utilise the natural land surface (without major recontouring), it is useful to
understand the original soils and landscape so that the
development can be designed to best fit the site and soil
properties. For example, the existence of naturally deep
permeable, soils can save the construction of costly drainage,
runoff, and irrigation works. Urban development without
recontouring is mainly used in lower density developments.
46
3 Anthropic Soils