The following are minimum permit requirements for installing discharge/intake pipelines in the Mississippi and Atchafalaya Rivers:
- The mouth of discharge/intake pipelines must be located below the Low Water Reference Plane (LWRP).
- The mouth of discharge pipelines must not face down towards the riverbed.
- The discharge outlet must be positioned at an elevation which prevents revetment and/or natural ground disturbance at all river stages. The mouth of intake pipelines must have screens to prevent debris accumulation.
- Pile structures supporting pipelines over a revetted area must be repaired in accordance with the June 1999 U.S. Army Corps of Engineers drawing titled "Repair Procedures when Penetrating Revetments with Piles, Caissons, and/or Pile Clusters" .
- The mouth of a discharge/intake pipeline must have a 5' minimum vertical clearance above the riverbed.
- If an applicant chooses to face the mouth opening of an intake pipeline down towards the riverbed, a 10' square blanket of stone shall be required to provide scour protection. The average required stone blanket thickness shall be based on water depths below LWRP:
Water Depth Average Thickness Inches
Less than 20' 14
Greater than 20' 18
The stone used shall be in pieces weighing not less than 6 pounds each, nor more than 200 pounds each meeting the following gradation:
Weight of Pieces (in pounds)
- 150 to 200
- 125 to 150
- 75 to 125
- 25 to 75
- Under 25
Percent of Total Weight
- 5 maximum
- 5 to 15
- 15 to 40
- 40 to 55
- 10 maximum