SELECTION OF STRUCTURES:
The consequences resulting from construction will determine
the choice of drainage structures:
1.
The impact of the changes on wildlife habitat on the lower
watershed.
2.
The constriction and consequent impounding of runoff above
the structure.
3.
The visual encroachment of the structure itself.
4.
The views outward from the roadway.
Vegetation along elevated structures will be different obviously
from vegetation grown on fill slopes; the former will favor wet
site species; the latter will favor dry site species. Our attitude
is on the side of preservation of natural vegetation provided that
sight distance not be obscured by vegetation.
