Maintaining a Healthy Lake

(by Russ Pitts)

 

Did you know that a lake is in many ways like a human body? Let me give you some examples. An unattended lake has a life expectancy similar to a human life (according to the Corps of Engineers). A human body requires constant diet and exercise to help keep our arteries clean. A lake requires constant silt maintenance and removal activities to keep its waters from becoming a silted marshland.

 

The waters of Lake Lure are unique in many ways, especially with the beauty of the surrounding mountains. These same mountains also pose a constant threat to the continued life of the lake. Every year, several thousand cubic yards of silt flow into the lake. This large number is due to the fact that waters of Lake Lure are located at the bottom of a very large mountainous watershed. The steepness of this watershed causes the waters to erode the very mountains we love. Any disturbances to the land, especially those next to the lake and tributary streams greatly accelerate the erosion-generated sediments filling the lake.

 

Dr. Morse had the foresight to address this challenge when the lake was originally built, and actively encouraged the surrounding landowners to be sensitive as to how they disturbed the land.

 

There are many areas around the entire lake that are experiencing silting, but none compares with the headwaters of the lake. It's a hard thing to see this silting occur unless you happen to have a depth gauge on your boat, and are constantly monitoring the changes. Fortunate for you we have a town council, town manager, lake advisory committee, and town volunteers who have been watching this for you. This is not something new. It's something that we have had to deal with since the gates on the dam were initially closed.

 

Did you know that we have historically had to dramatically lower the waters of Lake Lure approximately every ten years to allow excavation of the headwater areas of the lake? This is an extremely expensive task. For example, the last major excavation occurred in 1997 after the flood of '96. This particular excavation process cost well over a million dollars. Taking into account the historical trends, we are nearing the time when we might have to perform this again (actual time depends on the storms and amount of erosion). In the year 2004, we had a silt plume extending a quarter of a mile from the headwaters of the lake out into the main channel of the lake. This silt plume has reduced the depth of some waters from 20 feet to 10 feet in depth since the last excavation in 1997.

 

In response to this silt challenge, our current town leadership is taking a more comprehensive approach to addressing silting of the lake. This expanded approach does not eliminate the eventual need to perform costly excavations, but rather extends the period between excavations. The town plans to employ a self-funding concept wherever possible to minimize cost to tax payers. The new approach is based on addressing the challenge from four perspectives, which are:

 

1. Preventive Sediment Containment - prevent and capture pre-stream entry

 

2. Passive Silt Capture - capture before entering main lake body without dredging

 

3. Active Silt Capture - creation and maintenance of silt capture beds with ongoing dredging

 

4. Excavation - lowering of lake and removal of silt through mechanical means.

 

The main thing for you to know is that all four perspectives are necessary to create an effective, ongoing solution to our silt challenge. The town leadership is actively moving on all four perspectives, which includes the creation of a lake silt management and removal strategy.

 

The following outlines a few of these activities currently occurring:

 

Preventive Sediment Containment - town partnership/support with the Upper Broad River Watershed Protection Program (Currently headed by Clint Calhoun)

 

Passive Silt Capture - reviewing and pricing new passive capture technologies

 

Active Silt Capture - repair and updating of the town owned dredge (Includes silencing package), as well as training staff

 

Excavation - commitment to set aside funds on an annual basis for future expenditure

 

In closing, I want to encourage you to support the town leadership in their demonstrated commitment to protect our town's most valuable asset - the lake. Our lake is something worth preserving, and it will require all of us working together to achieve this community wide goal.