Hey UpaTree. I know you are not State side right now and thank you for your service, but I just happened to find this post so thought I'd chimie in.

I work as a consultant in VA as a wetland delineator and getting permits for wetland impacts for clients.

Your project as described does not qualify for an RP5 (regional permit 5) as suggested by an earlier poster. Since you are excavating your pond and not impounding the creek that permit will not work. It sounds like the 'mosquito pond" you want to excavate would be classified as a wetland though. If you are going to excavate (dig out with a back hoe), the Army Corps of Engineers does not have jurisdiction over that kind of work. They will not issue a permit for that. However, in Virginia the State Department of Environmental Quality does have jurisdiction over those wetlands so you will need to get a permit from them.

You will qualify for a WP1 - Virginia Water Protection Permit for Impacts Less than 1/2 acre, provided that your impacts stay below this. Keep in mind that if you impact over 1/10 of an acre you will be required to mitigate. I know it sounds crazy that they make you mitigate for building a pond out of a wetland (they are kind of the same thing), but they will because you are changing it from a forested wetland to and open water system. Different functions and values. However, in my experience you have to mitigate as if you built a parking lot and not a pond. This is up to the discretion of the Agency rep you are dealing with, so you may get by with less mitigation. Do your best though to keep it below a 1/10. In your area wetland credits are going between $55K - $65K per acre. And for impacting forested wetlands you have to mitigate at a 2:1 ratio.

Before you do anything have the wetlands and stream boundaries delineated and confirmed by the COE. You can hire a consultant like me, or request that the COE does the delineation. Alot of people get consultants to do this, because it speeds up the process. The COE will delineate wetlands, but it is low on their priorty list and happens when they can get to it. Vinny Pero is your COE guy as mentioned earlier. He is probably one of the best COE reps we have in the state and I've met most of them. Go over your ideas with him and he will give you good advice on how to proceed even if the project (only excavation and no placement of fill) is outside of his jurisdiction.