Tyler, In our county we have both the county NRCS office as well as a regional office. The regional office has the engineers who do dams, lagoons, etc. Just give the office in your county a call and they should be able to direct you to the right place. It seems like it varies around the country.
Worst case, if the NRCS doesn't have the personnel or ability to do the work, there should be some engineering firms in the area. They would cost you something (compared to it often being free with NRCS). The other thought would be to see if the US Fish and Wildlife Service has any offices close to you. Up here they have a "partners in wildlife" program where they can provide technical assistance as well.
Good luck,
Bill
