The new regulation applies to all SPGP-01 permit applications received after September 1, 2004 AND all applications pending as of September 1, 2004 – another big surprise, as usually regulatory changes have some transition period. NWP permittees were made aware in a July 26, 2004 public notice that this change will be effective September 1, 2004, and the August 17th edition of FieldNotes reported it was expected that this requirement would apply to a future version of the SPGP, and to expect them for all Individual Permits (IPs). Usually, however, at least a 30-day notice is given.

If you do not bridge or use a bottomless culvert to cross a stream, your pipe/culvert will need to be increased in size to accommodate the hydraulic restriction of countersinking. And, if you depress all cells of a multiple-cell culvert, remember that many regulators interpret the low flow permit condition to require that one cell be designed to contain the low flows in order to prevent the disruption to aquatic life in a stream from spreading flow over a wider area.

Historically, this has been handled by using a 6-inch timber or concrete curb (inlet and outlet) in the low flow culvert and a 12-inch timber or concrete curb in the remaining cells, as shown in the linked culvert detail.

The following links provide additional information:

• August 17, 2004 FieldNotes
• July 26, 2004 COE Public Notice
• September 1, 2004 COE Public Notice
• Revised NWP and SPGP Norfolk District Regional Conditions