We keep reinventing the wheel again, and again, and again...and again. Again.
Create a template project management plan and guide for website and web application contracts and projects.
Create a bunch of standard requirements and checklists. Update them annually. Ensure that all new and upgraded sites follow this template.
That way you can ensure that most of the non-business specific requirements for government websites and applications are met and included in the contract and project planning. In addition, you can help standardize the skills, languages, frameworks, platforms, APIs, etc.