Current through Register Vol. 35, No. 18, September 24, 2024
Primary roads shall meet the requirements of
19.8.20.2076 NMAC
and the additional requirements of 19.8.20.2077 NMAC.
A. Certification. The design and construction
or reconstruction of primary roads shall be certified by a qualified registered
professional engineer as meeting:
(1) the
requirements of 19.8.20.2076 NMAC;
(2) current, prudent engineering practices;
and
(3) any design criteria
established by the director; and
(4) shall include a statement that the road
has been constructed or reconstructed as designed and in accordance with the
approved plan; and
(5) at a
minimum, a static factor of safety of 1.3 for all embankments.
B. Location.
(1) To minimize erosion, a primary road is to
be located, insofar as practical, on the most stable available
surfaces.
(2) Stream fords of
perennial or intermittent streams by primary roads are prohibited unless they
are specifically approved by the director as temporary routes during periods of
road construction.
C.
Drainage control.
(1) Each primary road shall
be designed, constructed or reconstructed, and maintained to have adequate
drainage control, using structures such as, but not limited to, bridges,
ditches, cross drains, and ditch relief drains. The drainage control system
described in Paragraphs (1) through (6) of Subsection C of 19.8.20.2077 NMAC
shall be designed to pass the peak runoff safely from a 10-year, 6-hour
precipitation event or such greater event as may be specified by the
director.
(2) Drainage pipes and
culverts shall be constructed and maintained to avoid plugging or collapse and
erosion at inlets and outlets.
(3)
Drainage ditches shall be designed and maintained to prevent uncontrolled
drainage over the road surface and embankment. Trash racks and debris basins
shall be installed in the drainage ditches where debris from the drainage area
may impair the functions of drainage and sediment control structures.
(4) Culverts shall be designed, installed,
and maintained to sustain the vertical soil pressure, the passive resistance of
the foundation, and the weight of vehicles using the road.
(5) Natural stream channels shall not be
altered or relocated without the prior approval of the director in accordance
with 19.8.20.2009 - 2012 and 2025 NMAC.
(6) Except as provided in Paragraph (2) of
Subsection B of 19.8.20.2077 NMAC, structures for perennial or intermittent
stream channel crossings shall be made using bridges, culverts, low-water
crossings, or other structures designed, constructed, and maintained using
current, prudent engineering practices. Low water crossings shall be designed,
constructed, and maintained to prevent erosion of the structure or streambed
and additional contributions of suspended solids to streamflow.
D. Surfacing. The surfacing of
primary roads shall be rock, crushed gravel, asphalt, or other material
approved by the director as being sufficiently durable for the anticipated
volume of traffic and the weight and speed of vehicles using the
road.
E. Maintenance. Routine
maintenance for primary roads shall include repairs to the road surface,
blading, filling potholes, and replacing surfacing material. It shall also
include, as necessary, revegetation, brush removal, and minor reconstruction of
road segments.
