(1) Lack of adverse effect for change applications is generally based on the applicant's plan showing the diversion and use of water and operation of the proposed project will not exceed historical use, and can be implemented and properly regulated. A written narrative must be provided addressing the applicant's plan to prevent potential adverse effects to existing water rights, certificates, permits, and water reservations.

(2) The applicant's plan must document the effects to the other water rights including, but not limited to, the following:

(a) water rights using the existing or proposed point of diversion;

(b) other ditch users;

(c) down-slope water users;

(d) the effect to water rights dependent on the return flow;

(e) the effects of changing the historical diversion pattern including rate and timing of depletions;

(f) for groundwater applications, the applicant shall explain how the changed water right will affect water levels in wells of junior and senior water rights and the rate and timing of net depletions from hydraulically connected surface waters, and what effect those changes will have on those water rights within the notice area.

(3) The department must consider historical use in determining whether changing the water right would constitute an enlargement of the original water right.