(1) Except as specified in subsections (2) and (3) of this section, an applicant for a development permit shall submit estimated water supply requirements for the proposed development in a report prepared by a registered professional engineer or water supply expert acceptable to the local government. The report shall include:

(a) An estimate of the water supply requirements for the proposed development through build-out conditions;

(b) A description of the physical source of water supply that will be used to serve the proposed development;

(c) An estimate of the amount of water yield projected from the proposed water supply under various hydrologic conditions;

(d) Water conservation measures, if any, that may be implemented within the development;

(e) Water demand management measures, if any, that may be implemented within the development to account for hydrologic variability; and

(f) Such other information as may be required by the local government.

(2) If the development is to be served by a water supply entity, the local government may allow the applicant to submit, in lieu of the report required by subsection (1) of this section, a letter prepared by a registered professional engineer or by a water supply expert from the water supply entity stating whether the water supply entity is willing to commit and its ability to provide an adequate water supply for the proposed development. The water supply entity's engineer or expert shall prepare the letter if so requested by the applicant. At a minimum, the letter shall include:

(a) An estimate of the water supply requirements for the proposed development through build-out conditions;

(b) A description of the physical source of water supply that will be used to serve the proposed development;

(c) An estimate of the amount of water yield projected from the proposed water supply under various hydrologic conditions;

(d) Water conservation measures, if any, that may be implemented within the proposed development;

(e) Water demand management measures, if any, that may be implemented to address hydrologic variations; and

(f) Such other information as may be required by the local government.

(3) In the alternative, an applicant shall not be required to provide a letter or report identified pursuant to subsections (1) and (2) of this section if the water for the proposed development is to be provided by a water supply entity that has a water supply plan that:

(a) Has been reviewed and updated, if appropriate, within the previous ten years by the governing board of the water supply entity;

(b) Has a minimum twenty-year planning horizon;

(c) Lists the water conservation measures, if any, that may be implemented within the service area;

(d) Lists the water demand management measures, if any, that may be implemented within the development;

(e) Includes a general description of the water supply entity's water obligations;

(f) Includes a general description of the water supply entity's water supplies; and

(g) Is on file with the local government.