It takes a total of 2 years
for filled marsh cells to settle
Bolivar Marsh patterns of creeks and
marshes, 2008
Hurricane damage at Bolivar Marsh
Overview
The Port of Houston Authority (PHA) and the U.S. Army Corps of Engineers, in accordance with the Beneficial Uses Group (BUG) Plan has constructed approximately 800 acres of inter-tidal salt marsh adjacent to the north side of the Bolivar Peninsula.
2000-2003
The initial construction of Bolivar Marsh, begun in 2000, consisted of three marsh and open-water cells. These cells were designed to accommodate the first 15 years of dredging from the Lower Bay of the Houston-Galveston Navigation Channels (HGNC) while providing maximum inter-tidal marsh habitat. Cells 1 and 3 (320 acres and 250 acres respectively) were constructed and filled to create inter-tidal marsh.
The 200 acres of Cell 2 were to remain open as shallow lagoon or marsh habitat until the first maintenance dredging event occurred. However, because of an abundance of HGNC dredged material, Cell 2 was partially (about one-quarter) filled in 2000. Approximately 50 acres of Cell 2 was filled and began to meet the BUG’s marsh standards, developing sloped marshy edges and meandering tidal creeks to provide fishery ingress and egress. Despite problems with soft mud bottoms in this cell, large populations of shorebirds during late winter, low tide periods, indicated these bottoms made excellent invertebrate habitats.
2004-2007
While Cells 1 and 3 developed some excellent marsh ponds, they still lacked enough deeper pools and channels for water circulation and the marine production characteristics of natural marshes. In 2004, additional drainage channels were excavated. As a result, both Cell 1 and Cell 3 continued to dry and settled to the target elevation (0.6 feet to 1.4 feet Mean Low Tide, or MLT).
In 2005, Hurricane Rita damaged the levees and geotubes used for shore protection. In late 2006 and early 2007, many of the geotubes were replaced with riprap and additional channels were excavated. The northwest corner of Cell 1 was breached to allow wave energy and hydrology to naturally cut channels. Additionally, two breaches in Cell 3 were excavated to facilitate circulation of the marsh. As a result, extensive marsh vegetation, both inter-tidal (Spartina alterniflora) and salt-flat (Psuedo, Salicornia and Batis), developed in Cells 1 and 3.
2008-present
On September 13, 2008, Hurricane Ike ripped through the Galveston-Bolivar area damaging the levees and rendering the remaining geotubes non-functional. However, the marsh was not damaged.
As part of a combined effort to repair and protect the Bolivar Marsh levees, additional creeks and ponds will be cut into Cells 1 and 2 to enhance the fisheries habitat. In addition, the levees and shore protection will be repaired. The remaining geotubes will be replaced with rip-rap shore protection. An additional approximate 300 acres of marsh will be created to the northeast and adjacent to Cell 3 using a combination of materials dredged from Cells 1 and 3 to create the creeks and ponds in combination with other construction methods. Construction of the repairs and enhancement features will begin in the summer of 2010 and is expected to be complete in the fall of 2011.
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Overview
