2.1 |
This standard was
generally derived from the Watercourse Alterations Technical
Guidelines of the NB Department of Environment. |
2.2 |
The NB Department of
Environment Watercourse Alteration Regulations and Guidelines will
apply to all projects including Regulation 90-80 and 90-120 under
the Clean Water Act as revised in 1993. |
2.3 |
Erosion control
works shall be placed along the bank of the watercourse in such a
manner as will keep encroachment into the main channel, incised
channels and the flood plain to a minimum. |
2.4 |
Any construction due
to the erosion control work shall be evaluated for backwater
effects, increase velocity, redirection of flow and scour
effects. |
2.5 |
The foundation of
erosion control works shall be designed so that there will be no
embankment failures. The possible scour depth below the protective
works should be evaluated. |
2.6 |
The material used
for erosion control works must not come from the bed of the
watercourse and shall be clean, inorganic, non-ore-bearing and
non-toxic. Necessary filter layers shall be incorporated to prevent
loss of fine material. |
2.7 |
Erosion control
works should be designed to withstand water forces from buoyancy,
high velocity, wave action. The forces due to ice movement must also
be evaluated in the design. |
2.8 |
Rip rap shall meet the minimum size and gradings in tables 1 and 2. The largest stone size shall be 1.5 times the D50 and the minimum thickness of rip rap shall be 2.5 times the D50. |
2.9 |
Some materials used
for stream bank protection are: Good grass/sod cover; Rip-rap; Rock
filled wire baskets and/or timber cribs; Filter cloths; Concrete
blocks of various shapes; Stone (sloped and graded as per
design);Wood, concrete and steel linings. |
2.10 |
Following
construction a 5.0m (16 ft) riparian zone or buffer strip should be
established along the watercourse banks. Cultivation and livestock
access should be restricted from this area. A vegetative cover
should be established with plants capable of having dense growth and
fibrous roots and provide complete soil cover. |
2.11 |
Many techniques are
used for controlling erosion such as rock placement, retaining walls
and jetties. In the Maritimes the most common method is a rock slope
protection. For this type of erosion control, the design should be
carried out using the extensive literature on the subject so the
proper size(s) and slope(s) can be
determined. |