If during construction or operation a permitholder determines (1) that an additional amount of water is or will be required for the proposed use set forth in a permit issued pursuant to section 46-683 or (2) that there is a need to amend any condition set forth in the permit, the permitholder may file an application to amend the permit. Following a hearing conducted in the manner prescribed by section 46-680, the director shall issue a written order containing specific findings of fact either granting or denying the proposed amendment in accordance with the public interest considerations enumerated in section 46-683. An application to amend a permit shall not be approved if the amendment would increase the daily peak withdrawal or the annual volume by more than twenty-five percent from the amounts approved in the original permit, except for an amendment to increase the maximum daily volumetric flow rate or annual volume to levels authorized under a permit issued by the Department of Environment and Energy pursuant to section 81-1504 and subsection (9) of section 81-1505.