Freshwater Bayou Bank Stabilization (ME-13)

By placing riprap in front of the existing shoreline, further wetland loss will be decreased dramatically. It is anticipated that open water areas behind the rock structure will accumulate sediments and eventually become vegetated.

Location

This project is located along the west bank of Freshwater Bayou Canal near Little Vermilion Bay, 4 miles southwest of Intracoastal City, Louisiana, in Vermilion Parish. It
extends north from North Prong and Belle Isle Bayou to Sixmile Canal.

Problems

Increased tidal action, saltwater intrusion, and boat wakes have accelerated erosion long the banks of the Freshwater Bayou Canal. The spoil banks have completely eroded in some areas. The remaining spoil banks along the southern reach of the project area separate Freshwater Bayou Canal from several interior marsh ponds. If the banks breach, shoreline erosion will accelerate interior marsh loss.

Restoration Strategy

The objective of this project was to prevent further wetland loss through the reduction of bank erosion and subsequent tidal scour of shoreline marshes. Approximately 23,193 linear feet of freestanding rock dike were constructed in shallow water along the west bank of Freshwater Bayou Canal (from its confluence with Sixmile Canal on the northern end and North Prong to the south).

Progress to Date

The local cost share for this project was provided by Acadian Gas Company. Construction began in March 1998 and was completed in May 1998. The monitoring plan was approved in February 1997. To date, monitoring has consisted of documenting the pre-construction shoreline position relative to the rock dike and a land-to-water analysis of the preconstruction aerial photography that was taken in January 1997. This project is on Priority Project List 5.

The project is on Priority Project List (PPL) 5.

The Federal Sponsor is National Resources Conservation Service

The Local Sponsor is CPRA.

Approved Date: 1996
Project Area: 1,724 acres
Approved Funds: $5.56 M
Total Est. Cost: $8.91 M
Net Benefit After 20 Years: 511 acres
Status: Completed June 1998
Project Type: Shoreline Protection

GIWW – Perry Ridge West Bank Stabilization (CS-30)

Settlement plates such as the one pictured here will be used to determine if settling of the structure has occurred. Technicians from NRCS’s Crowley Watershed Office are shown taking baseline elevations before more rock is deposited. Future elevation readings will be taken after the structure is completed.

Location

The project is located along the northern bank of the Gulf Intracoastal Waterway (GIWW) between Perry Ridge and the Sabine River in Calcasieu Parish, Louisiana.

Problems

This section of the GIWW was dredged to allow the use of doublewide barges, and,  consequently, has intensified the occurrence of wake erosion. In addition, the construction of the Calcasieu Ship Channel and the deepening of Sabine Pass have increased the salinity and water currents within the GIWW. These activities have caused the GIWW shoreline to breach, thus impacting the interior marsh of the project area.

Restoration Strategy

Proposed project components involve installation of 9,500 feet of rock riprap along the northern bank of the GIWW from Perry Ridge to its intersection with the Sabine River.
An additional 2,200 feet of rock riprap will be installed from the Sabine/GIWW intersection north along the Sabine River. This proposed work is referred to as “construction unit number 2.” Approximately 22,952 linear feet of terraces will
be constructed in the shallow, open water areas north of the GIWW to reduce fetch (distance a wave can travel) and allow recovery of the interior marshes. Terraces will be
vegetated with 9,400 trade-gallon-sized plantings of California bulrush. This proposed work is referred to as “construction unit number 3.”

Progress to Date

Project construction is complete. The monitoring plan is currently in development and should be finalized in the spring of 2002.

The project is on Priority Project List (PPL) 9.

The Federal Sponsor is Natural Resources Conservation Service.

The Local Sponsor is CPRA.

Approved Date: 2000
Project Area: 1,132 acres
Approved Funds: $2.19 M
Total Est. Cost: $2.20 M
Net Benefit After 20 Years: 83 acres
Status: Completed
Project Type: Shoreline Protection