Coast 2050

Long before Katrina, people in Louisiana were aware of the environmental problems of the Louisiana coast (Fig. 3.55). In 1992, Andrew led to a lot of damage as well. The problems and strategic solutions were recognised and a vision was developed on a sustainable future for the Louisiana Coast: Coast 2050 (Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands Conservation and Restoration Authority, 1998).

The main problems are caused by hydrological changes and, contradictory, levees. Levees protect homes, businesses and farms from flooding, but they prevent sediments, that nourish the valuable marshlands, from reaching them. And

Fig. 3.56 Louisiana's coastal land loss between 1956 and 1990 (in red) (Source: Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands Conservation and Restoration Authority, 1998)

Fig. 3.56 Louisiana's coastal land loss between 1956 and 1990 (in red) (Source: Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands Conservation and Restoration Authority, 1998)

without these sediments, together with water and nutrients subsidence overtakes marsh growth: a net land loss (Fig. 3.56).

The hydrological changes add up to these problems. The North-South oriented canals cause an increase of saltier water and stronger tides in the marshlands. The East-West canals hold excess water on marshes and swamps. These conditions kill wetland vegetation and during hurricanes water rips up the marshland and erodes islands and shores. It is expected that 1000 mile2 of marsh and swamp will be lost in 2050 and changed into open water. And this threats the existing pipelines, wells, ports and roads, necessary for oil and gas extractions, if they are exposed to open water conditions. And this will be a costly threat.

The objectives to manage these problems are described in the Coast 2050 vision as follows:

1. Sustain a coastal ecosystem with the essential functions and values of the natural ecosystem;

2. Restore the ecosystem to the highest practicable acreage of productive and diverse wetlands;

3. Accomplish this restoration through an integrated program that has multiple use benefits; benefits not only for wetlands, but for all communities and resources of the coast.

The strategic solutions were made visible on a map (Fig. 3.57). The solutions manage and use the available natural forces, like the river, the climate and the rise and fall of the Gulf of Mexico. Solutions need to contribute to the creation of a sustainable marshland and a variety of habitats. The accumulation of sediments, the varying of salinities, the protection of key landforms and the exchange of energy and organisms contribute to these solutions. In the first place watershed management is proposed. River diversions, in order to restore a more natural hydrology, and improved drainage are the main measures. Secondly, watershed repair needs to be undertaken. The most important measures here are the restoration of barrier

Fig. 3.57 The Coast 2050 strategic solution for a sustainable ecosystem (Source: Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands Conservation and Restoration Authority, 1998)

islands, the closure of the Mississippi River Gulf Outlet navigation channel (as soon as possible), the building of two new Deltas by realisation of a 60 mile conveyance channel and the introduction of seasonal locks at the mouth of navigation channels in order to help marsh to recover from salinity stress.

All these measures cost a lot of money, but not implementing them costs even more on the long run.

The Coast 2050 report focuses mainly on restoration of the natural ecosystem of coastal Louisiana. It is expected that a natural functioning coastal system is better equipped to minimise the effects of storms, hurricanes and floods and improves the ecological and landscape quality in the area. The report does not focus extensively on flood protection and safety as such. Once a disaster happens, as it did with Kat-rina, all subtle and valuable objectives become out of sight, because all attention is going to immediate rescue and in a later stage to protection and safety. New plans are developed to meet these changed desires.

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