Since two to three months is normally required to process a routine application involving a public notice, you should apply as early as possible to be sure you have all required approvals before your planned commencement date.
For a large or complex activity that may take longer, it is often helpful to have a pre-application consultation or informal meeting with the Corps during the early planning phase of your project. You may receive helpful information at this point which could prevent delays later.
Pre-application consultation usually involves one or several meetings between an applicant, Corps district staff and interested resource agencies (Federal, State, or local). The purpose of such meetings is to provide for informal discussions about the pros and cons of a proposal before an applicant makes irreversible commitments of resources (funds, detailed designs, etc.).
The process is designed to provide the applicant with an assessment of the viability of some of the more obvious alternatives available to accomplish the project purpose, to discuss measures for reducing the impacts of the project, and to inform him of the factors the Corps must consider in its decision making process.