Current through Register Vol. 18, September 20, 2024
(1) The department shall include an
assessment of cumulative watershed effects on projects involving substantial
vegetation removal or ground disturbance. Using the analysis, the department
shall ensure that the project will not increase impacts beyond the physical
limits imposed by the stream system for supporting its most restrictive
beneficial use(s) , when considered with other existing and proposed state
activities for which the scoping process has been initiated. The analysis shall
identify opportunities, if any exist, for mitigating adverse effects on
beneficial water uses.
(a) The department
shall determine the necessary level of cumulative watershed effects analysis on
a project level basis. The level of analysis shall depend on the:
(i) extent of the proposed activity;
(ii) level of past activities;
and
(iii) beneficial uses at
risk.
(b) The department
shall complete a coarse filter screening on the following projects:
(i) upland timber harvest and salvage harvest
of more than 15 acres or 50 mbf;
(ii) RMZ harvest of green timber;
(iii) salvage harvest within the RMZ of one
or more acres of dead and dying timber;
(iv) new road construction greater than 0.5
miles;
(v) new road construction
located within an RMZ; or
(vi)
construction of any length of new road that includes the installation of new
Class 1 stream crossings.
(c) The department shall complete a
preliminary watershed analysis on projects when coarse filter evaluations
determine there is anything other than low potential for cumulative
impacts.
(d) The department shall
complete a detailed watershed analysis when coarse filter screening or
preliminary analysis predict or indicate the existence of unacceptable
cumulative watershed effects as a result of the proposal.
(e) The department shall establish threshold
values for cumulative watershed effects on a watershed level basis.
(f) The department shall determine thresholds
for cumulative watershed effects by taking into account such items as:
(i) stream channel stability;
(ii) beneficial water uses; and
(iii) existing watershed
conditions.
(iv) The department
shall set threshold values at a level that ensures compliance with water
quality standards and protection of beneficial water uses with a low to
moderate degree of risk.
(g) The department shall set threshold values
for cumulative effects associated with projects proposed in the watershed of a
water quality limited water body at a level that provides for protection of
beneficial water uses with a low degree of risk.
(2) Whenever feasible, the department shall
cooperate with other landowners in watersheds with mixed ownership to minimize
cumulative watershed effects within acceptable levels of risk.
AUTH:
77-1-202,
77-1-209,
77-5-201,
77-5-204,
MCA; IMP:
77-5-116,
77-5-204,
77-5-206,
77-5-207,
MCA
