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| Figure 1. Conventional steep slope
reclamation with uniform slope gradient, gradient terrace, and rip-rap lined downdrain |
Conventional land-shaping practices are often based on conveying or capturing runoff from an extreme event. These conventional practices include grading slopes to a uniform gradient, building gradient terraces across slope faces, and constructing rip-rapped down drains to convey runoff as shown in Figure 1.
Use and Cost Limitations of
Conventional Approach
Conventional designs often do not address the hydrologic balance
during less extreme flow conditions. This results in problems with
reclamation success for vegetation, livestock, and wildlife
post-disturbance land uses, high maintenance costs, and reclamation
bond complications.
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| Figure 1. Conventional steep slope
reclamation with uniform slope gradient, gradient terrace, and rip-rap lined downdrain |
The unnatural configuration of these designs does not provide the terrain diversity that creates spatial variation in water harvesting and slope aspect. The result is that vegetation tends toward a monoculture and animal habitat is minimized. The native land in the foreground of Figure 1 has forbes and shrubs growing near minor gullies, whereas the uniformly-graded slopes above them do not favor these plants, despite having been seeded with them.
Conventional land-shaping practices have high construction, maintenance, and liability costs. Terraces can be difficult and expensive to grade on steep side slopes. The rip-rap material may have to be procured off site and transported to the site. After construction, regular maintenance is often required as the terraces and ditches sized for extreme flows become clogged with sediment at lower flows, or are penetrated by burrowing animals. Clogged or burrowed terraces can result in catastrophic diversions of runoff from the terraces straight down the slope, often requiring major repairs.
Bonding Limitations of
Conventional Approach
The conventional approach to reclamation landform design affects
reclamation bonding liability and costs. The damage to the slope
from a blowout and related repair work can result in a reclamation
bond clock being restarted, which prolongs the operator’s period of
liability. The expense of creating land form designs has often
limited an operator’s ability to propose incremental reclamation
bonding for various stages of a project’s disturbance. For example,
an operator may determine that their greatest disturbance will
occur at year four of a five-year permit and they may post a bond
for that maximum disturbance, even though their liability will be
lower for the first four years. This creates an unnecessary
financial burden for the operator.