Summary of Public Comments, Responses, and Plan Modifications to the Draft 2006 South Carolina Aquatic Plant Management Plan

Note: All comments received refer to Lake Murray. No other comments were received.

Lake Murray:

Commenters: Sam Gustafson, George King, Roy Parker, Herlong (cherlong@greenwood.net), John & Heide Hoppe, Robert Shealy Jr., Robert King, Roger A. Becker, Julius A. Bell, Billy F. Peake, E. Gobbel, Mr. & Mrs. Henry C. Blakewood, Mary Autrey, Martin Blackford, Charles F. Noll Jr., David McElyea, Don & Deloris Rains, Michelle Elles, Jimmy & Cathy Woods, Harvey Cubb, Robert C. Rucker, Bernard H. Long, Hans N. Fagg, Tom & June Schmitt, Benji & Joe Barnhill.

Comments:

1. 300 acres...that's real impressive. As I recall prior to the carp the coverage on Lake Murray was several thousand acres. Congratulations and thanks to you and SCDNR for on a great job! (George King)

The 2006 Aquatic Plant Management Plan for Lake Murray looks fine to me. Thanks for the work you do to prevent the spread of invasive species of aquatic weeds. I think the grass carp stocked in 2003 have done a wonderful job of controlling hydrilla and Illinois Pondweed. Keep up the good work! (Parker)

2. We are concerned about the influx of weeds that prevents enjoyment of the lake. The plan calls for 4300 acres to be the trigger point for control action to begin. This is too high of a level to begin control actions. (Gustafson)

3. THE PURPOSE OF THIS LETTER IS TO MAKE IT CLEAR THAT THE HYDRILLA IS NOT GONE ... IT HAS JUST MIGRATED TO A TWO MILE LONG COVE WHICH IS SANDWICHED BETWEEN HIGHWAY 378 AND HORSE CREEK RD. The water adjoining our property had no nuisance vegetation until after the long drawdown for construction of the back-up dam. When the water returned in 2005, most of the cove quickly filled with hydrilla and a little water primrose. Because hydrilla is a perennial plant and because there are certainly tubers under the water and in the mud, we expect the hydrilla problem to explode when the weather warms. The property owners in this area of the lake need a three prong attack. Probably most importantly, we need to be scheduled for sterile grass carp stocking before the weed Gets a full grip on the cove this Spring. It would seem that early use of the appropriate herbicide might also help curtail the invasion. Finally, we may need commercial mechanical removal this Summer. (Hoppe, Shealy, Robert King, Becker, Bell, Peake, Gobbel, Blakewood, Autrey, Blackford, Noll, McElyea, Rains, Elles, Woods, Cubb, Rucker, Long, Fagg, Schmitt, Barnhill)

4. I think the drawdown alone was enough to control hydrilla for a couple years. Why didn't we learn a lesson from the effects of eradication of hydrilla from Santee? Total elimination has a negative affect on fishing and ducks. Why not find a balance? Hydrilla as we speak is no longer in Lake Murray. Why have a control plan? You have succeeded in killing it all and it can't come back with all the carp. (Herlong)

Response:

1. Even though no hydrilla was found in a late fall survey it shouldn’t be taken for granted that it is gone. The carp and the drawdown both helped to control the hydrilla and pondweed problems that were being experienced on the lake. However, hydrilla tubers and pondweed seeds are still viable and abundant in Lake Murray. The goal is to provide long-term control of these invasive species, which will take several years to fully assess.

2. The trigger mechanism of 4300 acres of hydrilla only applies to use of grass carp. Other control activities may be initiated at lower infestation levels. This year’s plan is consistent with the 2005 plan. The 2006 plan calls for no stocking of grass carp on Lake Murray unless hydrilla coverage exceeds 4,300 acres above the 330-foot contour at which time the Aquatic Plant Management Council may reconsider the need for additional grass carp. A late fall survey showed no appreciable hydrilla, so a dramatic increase in that acreage would have to occur to consider stocking more carp. However, this year’s plan does include the option of select herbicide control around municipal water intakes and high traffic landings if needed.

3. A survey of this area by SCDNR staff and discussions with SCE&G staff familiar with the area in question indicate that a plant other than hydrilla caused the problem. Water primrose and different terrestrial vegetation are routinely being confused with hydrilla. The drawdown exposed a lot of unvegetated shoreline where water primrose quickly spread and re-established at the 345-348 foot contour level. Water primrose is normally a shoreline species. It extends out into the water but is rooted close to the shoreline. While this plant can be invasive and cause localized problems, it has been in the lake for decades and is typically not a threat to general public access and use of the waterway. Based on past experience, it is expected that most of the plants that are rooted in deep water will not survive after the lake level returns to full pool. Another problem associated with primrose control is that all available herbicides require some set back or water use restriction for irrigation or potable water. Therefore, there are no plans to control its growth this year. However, the SCDNR and SCE&G will monitor aquatic plant growth in this area and reconsider control options as needed.

4. Drawdowns have a limited effect on hydrilla. Normally for 2–3 years after a drawdown, the zone where the drawdown occurred has little hydrilla growth. However, large amounts of hydrilla still existed in the areas below the drawdown level and still presented major problems. Although hydrilla was under control last year, a plan is needed to address the potential for regrowth of hydrilla and Illinois pondweed this year.

Plan Modifications:

None at present.