Fritchie Marsh facts for kids

Fritchie Marsh is a large wetland area, about 6,291 acres, located near Slidell, Louisiana, USA. It's a special type of land where water meets land. This marsh was once a freshwater marsh, meaning it had mostly fresh water. But over time, it changed into a mix of intermediate and brackish marsh, which means it has more salt water. There was even a risk of it becoming open salt water!

To save this important area, a group of conservation organizations started the Fritchie Marsh Restoration Project. Their goal was to bring the marsh back to its original freshwater state. The project started well and showed good results. However, it faced a huge setback when Hurricane Katrina hit in 2005.

What Kind of Marsh Is It?

When Fritchie Marsh was first studied in 1956, it was a freshwater marsh. Today, it's known as an intermediate and brackish marsh. The main difference between these types of marshes is how much salt is in their water, which we call salinity.

• Freshwater marsh: Has very little salt, usually less than 2 parts per thousand (ppt).
• Intermediate marsh: Has a bit more salt, averaging around 3.3 ppt.
• Brackish marsh: Has even more salt, averaging about 8 ppt.

The amount of salt in the water affects the plants and animals that can live there. Freshwater marshes have the most different kinds of plants and animals. As the water gets saltier, fewer types of plants and animals can survive.

Plants in Fritchie Marsh

In the intermediate parts of Fritchie Marsh, you'll mostly find a grass called salt marsh hay. You might also see big cordgrass and alligator weed. Salt marsh hay is very tough and can grow in many different salt levels. That's why it's also the main grass found in the saltier, brackish parts of Fritchie Marsh. Another plant that likes salty water is salt grass.

When the water in a marsh gets saltier, it can change from an intermediate marsh to a brackish marsh. Experts believe this change is happening in many wetlands in Louisiana because more salt water is flowing in.

Why the Marsh Was in Trouble

The main reason Fritchie Marsh started to change and lose its wetland areas was because it became surrounded by highways.

• Louisiana Highway 433 was built along its southern and eastern sides.
• Louisiana Highway 90 formed its western border.
• Louisiana Highway 190 was on its northern side.

Even though it's not 100% proven, many people think these highways had a big negative impact on the marsh.

How Highways Affected the Marsh

Fritchie Marsh naturally gets its fresh water, nutrients, and sediment from the West Pearl River. This flow is super important for keeping it a healthy freshwater marsh. However, when the highways were built, they cut off the marsh from many of these vital supplies from the river.

A small culvert (a pipe or tunnel) under Louisiana Highway 90 allowed only a tiny bit of water from the West Pearl River to enter the marsh. At the same time, salt water from Lake Pontchartrain started to flow into the area. This happened through Little Lagoon and the W14 canal, especially during strong winds and high tides.

So, the marsh was getting less fresh water and sediment, and more damaging salt water. This combination caused Fritchie Marsh to change from a freshwater marsh in 1956 to a mostly brackish marsh by 1990. Conservationists worried that if this continued, Fritchie Marsh would be completely destroyed and turn into an open body of salt water.

The Fritchie Marsh Restoration Project

To save the marsh, the Fritchie Marsh Restoration Project was approved in 1992. It was designed to restore the natural water flow, or hydrology, to about 5,941 acres of the marsh. The project was estimated to cost $2.2 million. The goal was to restore 1,040 acres of marshland over 20 years.

Getting Started

By October 2000, the project had found both federal and local sponsors. The Louisiana Coastal Protection and Restoration Authority in Baton Rouge became a local sponsor. The Natural Resources Conservation Service joined as a federal sponsor.

The main idea was simple: bring back the natural water flow, and the marsh would heal itself. But making this happen was complex.

• First, they needed to greatly increase the amount of fresh water and sediment coming from the West Pearl River. They did this by making the culvert under Louisiana Highway 90 much bigger.
• Second, they needed to improve how water flowed through the marsh. They achieved this by digging out parts of a nearby area called Salt Bayou.
• Finally, they needed more fresh water to fight off the salty water intrusions. They built a special structure called a weir and redirected water from the W14 canal. This allowed fresh water runoff from the city of Slidell to flow into the marsh, bringing more fresh water, sediment, and nutrients.

The entire project was finished in February 2001.

Was the Project a Success?

In the first few years after the project was completed, Fritchie Marsh showed promising signs of improvement.

• Before the project (from 1996 to 2000), the marsh was losing about 126 acres of land.
• After the project (from 2000 to 2004), the marsh actually gained 13 acres! This was a small but steady gain of about 3.3 acres each year.

This showed that the project was working, slowly but surely, just as planned. Meanwhile, a nearby area that wasn't part of the project continued to lose marshland.

However, this positive trend didn't last. In 2005, Hurricane Katrina hit, causing massive damage. Between 2004 and 2010, Fritchie Marsh lost a huge amount of land: 916 acres. This means about 14.6% of the marsh was lost, at a rate of 152.7 acres per year. Satellite images from 2004 and 2005 clearly showed that Hurricane Katrina was directly responsible for this devastation.