Where determinations have been made by the division engineer, inquiries regarding the navigability of specific portions of waterbodies covered by these determinations may be answered as follows:
33 CFR § 329.15
Findings and determinations should be made whenever a question arises regarding the navigability of a waterbody. Where no determination has been made, a report of findings will be prepared and forwarded to the division engineer, as described above. Inquiries may be answered by an interim reply which indicates that a final agency determination must be made by the division engineer. If a need develops for an energency determination, district engineers may act in reliance on a finding prepared as in section 329.14 of this part. The report of findings should then be forwarded to the division engineer on an expedited basis.