2. Procedure for approval of project applications and establishing priorities therefor. If the agency, after study and investigation, is of the opinion that it would be in the public interest and for the protection of public health and welfare to undertake a project, it shall, with the approval of the board of supervisors, make application to the secretary of agriculture of the United States for assistance pursuant to section three of the said "Watershed Protection and Flood Prevention Act". Before such application is forwarded to the secretary of agriculture of the United States for approval, it shall be submitted to and approved by the water resources commission (hereinafter referred to as the "commission") prior to submission of the application to the secretary of agriculture. At the same time that an application is submitted to the commission, a copy thereof shall be forwarded by the agency to the state soil conservation committee, which shall, within thirty days after receipt of the copy of the application, submit any advice or comments to the commission. The commission is authorized to establish and amend a priority list for projects, and to establish rules and regulations for the handling and processing of applications, plans and projects. Such applications to the commission shall be accompanied by an outline of the project in general form indicating the purpose, size, scope and location of the contemplated project, the proposed works and facilities, and, when available, preliminary estimates of the total maximum cost of the project and the amount and nature of requested federal aid and local costs. The approval of the application by the commission shall not be deemed to be final approval of the project, or approval of detailed plans and specifications for the project, or to authorize the construction of any project works or facilities. The commission shall not be required to hold a hearing on such an application but, before disapproving any application, it may cause a public hearing to be held on the application to hear any and all interested parties.