A grassroots effort to save a Brevard County trail has pitted bike enthusiasts against a project that they say would destroy their beloved park.

The Grapefruit Trails have been around for about three decades. Many people on the Space Coast don't even know it's there, because it's situated in a public park in a Palm Bay neighborhood, near Babcock Street.

"It's only two miles long, but it's a dirt roller coaster where people can practice their skills and get better and better," said Murray Hahn, with the Brevard Mountain Bike Association.

Hahn said bike riders come from across the state, country and even the world to ride the course, which winds through woods and old oak trees. On weekends, the trail is packed.

"There are so many people who come out here, enjoy themselves and get their exercise," said bicyclist Richard Kohler.

But the trail may not be around for much longer. They're on the banks of the Melbourne Tillman Canal, built nearly 100 years ago to prevent flooding, erosion and excessive drainage in the southern part of Brevard County.

The district is some 64,000 acres in size, and leaders, along with the St. John's Water Management District, are planning to reslope the canal to prevent drainage into the struggling Indian River Lagoon.

"BMBA does a great job of updating the trail and building new features that are always challenging and fun," Kohler said.

The Brevard Mountain Bike Association spends about $10,000 of its own money each year to maintain and improve the trail, but the proposal may put an end to that.

"The cross sections that I've seen would remove 85 feet of that, which basically means the trail would go away," Hahn explained.

Supporters trying to save the trail want a sea wall built along the canal, but the canal district said that would cost between $6 million and $10 million. The sloping plan only runs in the $500,000 range.

"It's a good project," Hahn said. "They are trying to save the Indian River. All we are looking for is a way where we can keep riding our bikes."

St John's Water Management officials, along with the canal district, are set to meet Monday with representatives from the Grapefruit Trails to see if there are any alternatives to save the trails.