(1) The department shall use the following criteria to determine whether to implement angling restrictions in streams:

(a) angling pressure as determined by the department has the potential to contribute to excessive fish mortality; and

(b) one or more of the following environmental conditions has been determined by the department to exist:

(i) in nonnative salmonid streams designated by the department in the Statewide Fisheries Management Plan, daily maximum water temperatures equal to or exceeding 73 degrees Fahrenheit at any time during the day for three consecutive days;

(ii) in cutthroat trout streams designated by the department in the Statewide Fisheries Management Plan, daily maximum water temperature equal to or exceeding 66 degrees Fahrenheit at any time during the day for three consecutive days; 

(iii) in bull trout streams designated by the department in the Statewide Fisheries Management Plan, a daily maximum water temperature equal to or exceeding 60 degrees Fahrenheit at any time during the day for three consecutive days;

(iv) stream flows fall to or below the 5th percentile of daily mean values for this day flow level based upon hydrologic records for that water body; or

(v) water conditions meet the criteria for angling restrictions as stated in a drought management plan; or

(c) other biological or environmental conditions such as, but not limited to, water body pollution, disease, or concentration of angling pressure due to other restrictions or closures that the department determines have the potential to contribute to excessive fish mortality.

(2) A fishing closure may be implemented when:

(a) conditions of (1) develop or degrade;

(b) dissolved oxygen is equal to or less than 4 ppm when measured in the early morning before sunrise; or 

(c) water conditions meet the criteria for fishing closures as stated in a drought management plan.

(3) An angling restriction or fishing closure may be delayed or may not be implemented by the department if closure criteria are forecast to be met for a short duration.