Reprint TECHNIQUES FOR CREATING MINING LANDFORMS WITH NATURAL APPEARANCE Gord McKenna Senior Geotechnical Engineer BGC Engineering, Vancouver Tailings and Mine Waste ’09 Banff 2009 Gord McKenna, PhD, PEng, PGeol Senior Geotechnical Engineer #800‐1045 Howe Street Vancouver, BC V4K4S4 Canada Email: [email protected] or [email protected] www.bgcengineering.ca Phone 604‐838‐6773 Citation: McKenna, G. (2009) Techniques for creating mining landforms with natural appearance, Proceedings of Tailings and Mine Waste ’09 Conference. Banff, Alberta. November 1‐4, 2009. The University of Alberta Geotechnical Centre, Edmonton. TECHNIQUES FOR CREATING
MINING LANDFORMS WITH NATURAL APPEARANCE
Gord McKenna, Senior Geotechnical Engineer
BGC Engineering, Vancouver
ABSTRACT
Building on the successes of mine reclamation,
some mining companies, regulatory agencies, and
stakeholders are starting to require that reclaimed
mining landscapes and mining landforms have a
more natural appearance. At present, there is little
guidance on meeting this new requirement. While
most stakeholders aren’t clear just what they want,
they are often vocal in expressing what they don’t
want – monuments to mining such as terraced
pyramid-like waste rock dumps, long linear
drainage ditches, peneplain plateaus, trees planted
in straight lines (“plants on parade”), rectangular
ponds, and flume-like wetlands. Fortunately
several strategies and tools are available to
designers and operators to create reclaimed
landscapes that better meet society’s expectations
for natural appearance.
geotechnical stability) for the sake of aesthetics.
Methods, tools, and examples of successful
projects are included in this paper.
INTRODUCTION
The notion of designing mining landscapes to be
aesthetically pleasing is somewhat troubling to
many miners. Perhaps it is because mine design
involves constraints and trade-offs and is ultimately
a compromise of performance and economics –
some may feel that including aesthetics means
compromising on performance or cost or perhaps
that it goes against the effective spartan business
demeanor of many miners. Talking about industrial
design, Gelernter (1997) notes that “to pay money
for elegant technology is to seem unserious, selfindulgent, and arguably incompetent.”
One such approach, landform design, offers a
more holistic approach to design of mining
landscapes that incorporates a variety of
specialists including geotechnical, surface water,
groundwater, soils, vegetation, and wildlife. The
landform design toolkit includes tools like landform
grading, use of natural analogs, terrain analysis for
anthropogenic landscapes and new surface water
design and construction techniques that result in
more sustainable landscapes that more closely
resemble natural ones – ideally where form follows
function.
Perhaps concern about agreeing to create naturallooking landscapes relates to a lack of direction
and experience. And while beauty is in the eye of
the beholder, there is a general trend for regulators
and stakeholders to ask (or require) mines to
produce reclaimed landscapes that are more
natural-looking – to reduce the use of straight lines
and planar slopes, to use native species for
revegetation with trees and shrubs planted in less
regular patterns and in patches of size and shape
that mimic the surrounding terrain.
One tool is a cafeteria-style list of elements that
can be incorporated into reclamation designs.
Many of these elements are simple and costeffective to incorporate into designs and help to
provide greater landscape diversity and variety and
contribute to breaking up some of the linear and
planar patterns inherent in mining activities.
Architectural rendering techniques are being
applied in the design stages to get stakeholder buy
in and to better answer the question up front, “Will
the reclaimed landscape be natural-looking?”
Designers and operators need to remain vigilant
that the proposed changes to designs and
construction techniques do not adversely affect
environmental performance (and in particular,
Discussion of natural appearance is often framed
in terms of visual aesthetics. Related experiences,
such as auditory or olfactory aesthetics may also
be
important
or
implied. This paper
minces the terms
natural appearance
and aesthetics, and
thus overlooks the
fact that an elegant
concrete arch dam
can have high visual
appeal, very strong
aesthetic appeal, but
rather
unnatural
appearance. Rolston
(1998) and especially Cronon (1995) provide good
philosophical discussions of our historic and
modern meaning of the words “nature” and
“natural” and explore the implications for policy and
decision
making
that
are
important
to
understanding such topics as environmental
protection, mine reclamation, and have bearing on
the present topic.
This paper provides some background to the
issue, discusses the need for a more holistic and
multidisciplinary approach to landform design, and
more practically provides a cafeteria-style list of
landform design elements that can be employed to
make mining landforms have a more natural
appearance. Most of these elements are also
useful in creating habitat and diversity in the
landscape – embodying the idea of “form follows
function” from architecture and industrial design.
Learnings that went into this paper are largely
based on hands-on experience at two large oil
sands mines in northern Alberta (Syncrude
Canada and Suncor Energy), and reclamation
tours at about 100 mines in North America,
Australia, and Europe. The author has been
influenced by numerous colleagues, notably Horst
Schor of HJ Schor Consulting, Les Sawatsky of
Golder Associates, Marie Keys of Syncrude
Canada,
Andy
Robertson
of
Robertson
Geoconsultants, and Professors Dave Sego and
Nordie Morgenstern of the University of Alberta.
Artwork in this paper is provided by provided by
Derrill Shuttleworth of Studio Two in Edmonton.
STATE OF PRACTICE
Most mining landforms (dumps, dykes, tailings
ponds, channels, open pits) are designed for
geotechnical stability and efficiency of construction
(McKenna, 2002). They usually consist of
rectangular shapes, evenly-spaced benches
(terraces) with linear crests and toes, with angleof-repose slopes between them, and constant
elevation
crests
(peneplains).
Reclamation
involves regrading the intermediate slopes
between the berms to constant planar slopes (say
2H:1V or 4H:1V), smoothing out any irregularities,
covering with constant thicknesses of soil, and
planting vegetation at constant densities (stems
per hectare), often in long rows. Surface water
drainage features, where employed, are usually
retrofit during reclamation or afterwards, and
consist of long, linear, trapezoidal channels, often
of constant grade, often lined with uniform riprap.
However, most mines have at least one location
that breaks these rules. For example, a
roughened and sculpted dump slope, rockpiles
placed haphazardly on the landscape to provide
rodent habitat, a wetland with a shallow irregular
shoreline, a grove of shade trees, or a meander in
a watercourse. Usually individuals (artisans) are
responsible and take pride for these special areas.
These areas are often featured in a mine’s
promotional materials. A few mines have adopted
natural appearance criteria in the design of all new
landforms. See Table 1 for examples of each.
Table 1. Examples of mines using natural
appearance
Location *Anaheim residential, CA Falconbridge, ON Faro, YT Highland Valley Copper, BC Island Copper, BC *Line Creek Coal, BC *MiBrag Coal, Germany Millennium Chemicals, W. Aust. Molycorp, NM *Premier Coal , W. Aus. *Price Coal, UT SF Phosphate, UT *Suncor, AB Examples of elements employed Landform grading Preservation of historic areas Roughening Roughening, meandering creeks Sculptured shorelines, snags Dump roughing, sculpted coal waste piles Sculpted shorelines for pit lakes Slash spread on reclaimed areas Angle of repose planting Sculpted beaches, natural revegetation planting Slope roughening, diagonal swales Slash Landform grading, ridge mounds, irregularly shaped wetlands, native vegetation *Syncrude, AB Landform grading, roughening, ridge mounds, rockpiles, native vegetation *TransAlta Highvale, Landform grading, irregular AB ridgelines, tailored planting * indicates sites where most new landforms are designed to have natural appearance. Why natural appearance?
There are several reasons for trying to create
mining landforms that have natural appearance:
 to meet promises made to stakeholders
 to meet regulatory requirements
 for public relations value
 to create diversity in the landscape which in
turn promotes resiliency – a useful element of
landscape performance (Holling, 1973)
 to follow a mantra of “form follows function” – a
landscape that is design to exhibit similar
landscape performance (function) as the
natural environment ought to look natural too
(form).
The idea that “form follows function” was coined by
Sullivan (1896) while reflecting on the design of
high-rise office buildings. Sullivan explains, “It is
the pervading law of all things organic and
inorganic, of all things physical and metaphysical,
of all things human and all things superhuman, of
all true manifestations of the head, of the heart, of
the soul, that the life is recognizable in its
expression, that form ever follows function.”
Slightly more down to earth, Gelernter (1997)
states, “a useful object has a natural form which
when it is in complete harmony with its function is
perceived as having a special ‘rightness’ or ‘fit’ that
borders on art … its shape seems less designed
than at long last discovered.”
And why not?
There are cases where designers may chose to
build landforms that don’t have natural
appearances:
 Non-natural land uses. While many mine
landscapes are reclaimed back to natural
areas for wildlife habitat or forestry, some are
reclaimed to gardens, industrial areas, or held
for later remining. In these cases, natural
appearance may be undesirable.
 Preservation of historic resources. Miners are
often proud of the pits and dumps they have
constructed, and value their anthropogenic
nature above “hiding” them with regrading and
vegetation. Similarly, “ruins” of mining
buildings are often preserved as historic facility
as a reminder of a previous age.
 Ease of monitoring dams. In some cases,
planar slopes with linear crests, with slopes
simply grassed are easier to monitor that
sculpted landforms with diverse swales and
large trees. Similarly, flat benches provide


access to read and redrill geotechnical
instruments.
Avoiding geotechnical instability. There may be
instances where slopes that are marginally
stable could be affected by changes in slope
geometry – any changes for the purposes of
natural stability must honour the need for
geotechnical (and erosional) stability. Often
natural appearance and stability will go hand in
hand, if done well.
Hardrock pit walls. Most benched pitwalls are
generally considered too expensive to reclaim
and remain as unusual scenery.
Pitwalls are generally left unreclaimed
Other objections include: too expensive (not
usually the case), that beauty lies in the eye of the
beholder (yes, but there is often general
agreement on whether a particular design is
acceptable), efforts would be unmeasurable (yes,
though there have been attempts, doesn’t show
once trees have grown (often largely true, but can
be considered in design), and people like the
“mining” look (as some miners do), and that one
will never be able to fool everyone (but this is not
usually the intent).
Trends
Some regulatory agencies are mandating activities
to “improve” aesthetics. This is accomplished by
requiring mines to present closure plans showing
what final reclamation will look like, and then
requiring public approval for the plans. If the
proposal does not meet the approval of
stakeholders, the mine must adjust the plan. This
is one mechanism to address the subjectiveness of
aesthetics. Typically it is found that building for
natural appearance has the same cost as
traditional reclamation, can be done with medium
to large equipment, and is usually simpler than
traditional reclamation. Results are always
appealing to stakeholders and regulators, staff and
management. Thus the trend is for more and more
sites to desire or require design and construction
for a more natural appearance and the need to
defend traditional approaches in some situations.








Open vistas
High, steep terrain
Colourful terrain
Open water and rivers, especially clear water
Exposed bedrock, riverbanks
Rapids, falls
Rare or scarce scenery
Historic features
It is perhaps ironic that unreclaimed mining
landforms and landscape will often score quite
high in quantitative visual appeal systems,
especially when they offer scarce historic scenery
in otherwise natural areas. In contrast, a mining
landscape that is reclaimed to have a natural
appearance will often be indistinguishable from
natural landscapes to the casual observer,
particularly in forested regions.
Time to move the goalposts again! ASSESSING NATURAL APPEARANCE
There have been numerous attempts to score
natural
appearance
systematically
and
quantitatively. The literature offers guidance for
those interested. Among the more famous,
Leopold (1969a,b) developed a system for rating
natural appearance of river valleys using 46 factors
in three broad categories (physical factors, biologic
and water quality factors, and human use and
interest factors) and rated these factors on a scale
of 1 to 5. See also Carlson (1977), Litton et al.,
(1974) and Wilson-Hodges (1978) for other
systems.
Quantifying visual appearances has been
examined for other industries. For example,
highway engineering, transmission lines, quarries,
barriers and walls, and cell phone towers. While
much of the effort is directed towards halting
proposed projects or litigation with respect to real
estate values being degraded, the literature offers
advice on public perceptions and provides
landform designers with useful design information.
Much of the most useful information for miners is
available in methods and tools of mitigating visual
impacts of logging (e.g. British Columbia Ministry
of Forests, 1995).
Items that score highly in some of these schemes
include:
Because most people know what they don’t want,
and aesthetics is highly personal and cultural, the
author has found it more useful to take a
qualitative approach – using visual aids to
communicate what the landscape will look like
when reclaimed and seek input from stakeholders
and regulators. Accepting input, and making
changes, usually leads to acceptance of plans,
with a new onus on the miners to deliver what is
promised. Such a system forms the basis for
approval of municipal developments – architectural
renderings of the proposed designs are presented,
modified, and if approved, the owner is responsible
to live up to the presentation. Renderings of often
done in watercolours, or three-dimensional
models, or more recently computer-generated
artwork. The mining industry uses all of these
approaches, but inconsistently.
DESIGN AND CONSTRUCTION
APPROACHES
There are several approaches to
landscapes with natural appearances.
creating
Artisan approach
At most mines, there are one or more individuals
(often biologists, reclamation specialists, or heavy
equipment operators) that create areas in the
reclaimed landscape that are natural-looking and
have high aesthetic appeal for most visitors and
staff. Examples are provided in Table 1. These
examples tend to be one-off approaches to a few
areas of the mine site. Many are done “under the
radar.” Some win awards. These approaches can
be effective, sometimes costly, but are difficult to
apply at the landscape level (in other words,
across the whole minesite).
Landform design
If we argue that to achieve a natural appearance
that involves aspects of geotechnical, surface
water, groundwater, soils, vegetation and wildlife, a
multidisciplinary approach is needed.
In many cases, the integration of surface water
drainage into the design of dumps and dykes and
their associated plateaus, along with the use of
revegetation species found in the local
environment and planted logically (moisture-loving
plants in the swales, plants that tolerate drier
conditions on the ridges) following ecosite patterns
similar to the natural environment, will produce
largely natural-looking landscapes as an output of
the design (rather than an explicit input).
Landform grading
The multidisciplinary landform design team Landform design (McKenna, 2002) is one such
approach to the design and construction of mining
landscapes. Beyond the specialists listed above, it
also involves mine planners and operations people
and other specialists. The focus is on setting clear,
simple, and achievable landscape performance
goals, then involving designers, planners,
managers, and operators to build landscapes that
can be reasonably expected to meet these goals.
This paper argues that one of the goals that
deserves to be considered is natural appearance.
Landform grading was invented by Horst Schor a
generation ago and is applied to various large
residential and mining projects (Schor and Gray,
1995; Schor and Gray, 2007). Landform grading
attempts to mimic stable natural hillslopes and
involves shaping slopes to have natural
geomorphic patterns (swales and ridges) that fit
with the local geography and climate, supported by
vegetation compatible with slope hydrogeology.
Landform grading has been extended in the oil
sands region to also include dump plateaus and
tailings beaches, shaping these otherwise nearly
flat and planar features to having nested
watersheds and drainage patterns to support the
local land uses, vegetation, surficial hydrology and
groundwater hydrology.
Landform grading is one of the major tools
employed by landform design teams. Experience
has shown landform grading to be practical and
indistinguishable in cost from conventional grading.
It results in mining landforms that have natural
appearance and landscape performance that is
similar to the natural surrounding environment.
Landform design draws heavily on practical mine
reclamation experience, but also brings to bear
such disciplines as geomorphology, soil science,
wildlife science. The use of natural analogs (Keys
et al., 1995) is an important design tool – the idea
is to design mine plateaus, slopes, and streams to
mimic natural features in the region, arguing that
the natural features are products of the local
materials, climate, and processes over thousands
of years.
This formal approach to the design of landforms
and landscapes offers transparent and integrated
efforts, drawing on the weight of the engineering
design approach and the knowledge and creativity
of a wide variety of specialists.
Landform grading includes sculpting slopes into
microwatersheds using swales and ridges.
Landform grading applied to civil project often
required very tight survey control and extensive
monitoring and sign-off. In a mining environment,
there is more flexibility; much of the finer features
(swales, ridges, planting schemes, etc) can be
(and should be) field fit by a qualified field
supervisor and conscientious operators. While the
field construction costs are typically no higher with
landform grading, the level of engineering design
can be about double that of conventional design,
but still a tiny fraction of the project cost.
Item
creeks
4. Watershed
berm at crest
5. Irregular ridge
mounds
Landform grading of a small mine dump
6. Reslope
benches
DESIGN ELEMENTS
Table 2 provides design elements that can be used
as a cafeteria-style list for the design of landforms
with natural appearance. Some typical dimensions
are provided. All elements need design (either in
the office or the field) by qualified individuals and
signoff that regulations will be met, geotechnical
stability is assured, and that the elements will work
well together to provide the promised landscape
performance.
7. Wetlands at
toes
8. Tailored
planting
Table 2. List of landform design elements for
natural appearance
Item
1. Meandering
creek
2. Connect
swales with
natural
watercourses
3. Coversoil and
revegetate
bare areas,
Example
 Irregular 100-300 m wavelength,
Minimum amplitude = 1 to 2
creek widths
 Drain swales into adjacent
watercourses. Carry vegetation
patterns from natural gullies up
onto the dyke or dump slopes.
 Opportunity for aggressive
reclamation of exposed areas
near roads and creek slopes –
9. Swales on
slopes
Example
allow early reclamation and
general greening up of area.
 Push up dump material and
round the downstream crest as
final design feature.
 Horizontal wavelength 200 to
400 m, zigzag 0 to 20 m, vertical
height 2 to 4 m, 2.5 to 4H:1V
sideslopes with 3 to 5 m crest
width
 Australians call these “bunds.”
They can be built by using large
mining trucks and later shaping
the resulting line of spoil piles.
 To add diversity to skyline
profile, add irregularly shaped
mounds at the downstream crest
 Mounds can be 3 to 5 m high,
3H:1V sideslopes or flatter, 2030m wide, 30-80m long (2000 to
10,000 m3 each)
 Consider planting schemes to
enhance appearance.
 Mound heights should be
designed to be 5-15% of the
landform height to break up
sightlines.
 Mounds can be placed near the
crest – acting like false
storefronts in a Western town.
 When finished with benches,
reslope by regrading substrate or
adding additional reclamation
material.
 Make sure that access to place
reclamation material is left.
 Enlarge toe ditch (toe creeks!) to
create shallow wetland, 2 m
deeper than toe ditch invert
(where ditch invert is shallow)
 Consider 10-20 m wide, 30 to 60
m long (1000-5000 m3)
 Use irregular shoreline, very
shallow slopes, create mounds
with spoil
 Follow ecosite planting schemes
– tailor the planting to fit
conditions
 Consider planting swaths of
trees for visual patterns on
slopes
 Use this scheme to mimic
natural vegetation patterns
elsewhere
 Construct swales and ridges of
slopes to carry runoff safely to
the toes of dumps. Use diagonal,
elbow, and curvilinear shapes.
Hydrologic design required
above threshold watershed
Item
10. Reclaim
erosional fans
and gullies in
place
11. Irregular
shoreline
12. Littoral zone
13. Add
additional fill
at toe
14. Mounds on
plateaus,
benches,
slopes
15. Brushpiles /
snags
16. Rockpiles
17. LFH
placement
18. Microtopogra
phy
19. Coversoil
diversity
20. Access
controls
21. Viewing
platforms /
Example
areas and slope gradients.
 Once gullies are stabilized,
instead of ‘erasing’ them, simply
repair them in place
 Allows increased diversity,
reduced cost
 Need to remove the ‘cause’ of
the gully prior to fixup in most
cases
 Irregular shoreline should be
integrated with construction for
lakes, wetlands, marshes, and
fens.
 Build large littoral zones
(typically less than 2m deep) into
design of lakes
 Adding fill at toe to break up
straight lines and add
topographic diversity may be
desired
 Similar effect achieved by
reclaiming erosion fans in place
 Expensive if not a short haul /
short overhaul
 Small mounds on berms and
slopes for topographic diversity
 Can be pushed up or placed or
cut/fill from other projects
 Typically 10-30 m diameter, 3-5
m high (300-4000 m3)
 Field fit where practical.
 Temporary habitat improvements
can be made by having small
brush piles for small animals or
standing snags for raptors
 Build rock piles from siltstone for
animal habitat
 6 to 15 m diameter, 2 to 4 m high
 Place forest floor salvage in
islands to promote early
biodiversity
 Slash (coarse woody debris)
also enhances diversity and
habitat.
 Roughen slope to create
microtopography to enhance soil
moisture and diversity
 Use different prescriptions in
different areas to enhance
diversity
 Establish a plan for long-term
access to area
 Provide good access, but restrict
number of roads and type
 Use aesthetic design principles
from trail guides to guide
designs.
 Install viewing platforms for tours
and future recreational
Item
photo
locations
Example
opportunities.
FINAL COMMENTS
Creating natural-looking mining landforms and
mining landscapes is a creative challenge.
Successful reclamation of these landscapes will
involve a multidisciplinary team using a variety of
design tools and analyses. The results are
rewarding personally, for the team, the mining
company, and society. Formal design processes
are needed for many elements to avoid triggering
unintended consequences and for managing costs.
Ideally form will follow function, and the
landscapes will be both more visually appealing
and exhibit better landscape performance.
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