ISU SUGGESTED RESTORATION ALTERNATIVES

CLEAR LAKE RESTORATION

     Because high levels of nutrients already reside in Clear Lake, making changes to the lake itself to reduce is necessary.

 Dredging. One potential step that could decrease P-delivery to the main lake is dredging. If the Little Lake were dredged to its original volume, it would prevent 64% of the phosphorus that flowed into the little lake from entering the main lake. When combined with watershed phosphorus reductions discussed earlier, this would result in a 50% reduction in phosphorus loading to the main lake.

 No-wake zones. Another step which would help with the problem of sediment resuspension would be to enforce existing no-wake zones in the lake and perhaps expand the no-wake zones in some of the more vulnerable areas of the lake.

 Aeration. Aeration presently is an ongoing winter activity at Clear Lake. If the Little Lake is dredged, year around aeration of the Little Lake should be considered. The Little Lake will contain the deepest area of the lake, so aerating that basin would avoid anoxia and provide important wintering habitat for fish.

 Breakwater structures. The construction of breakwater structures has great potential to improve fisheries habitat and water quality at the same time. The diagnostic study showed that wind resuspension is a major problem for Clear Lake. Breakwaters placed parallel to existing bulrush beds would protect them from the pounding forces of the wind and waves.

 Fish population management. To address the problems with carp and bullhead populations in Clear Lake, it will be necessary to improve two critical areas. First, it would be necessary to improve water quality through the nutrient mitigation outlined above. This would help reestablish aquatic vegetation which so many other fish species are dependant upon. Second, it would be necessary to reduce and control populations of bottom-feeding fishes, primarily carp and bullhead.

     Although bacteria levels in Clear Lake have been well below EPA criteria, eliminating as much bacteria from the lake as possible is an important step in improving Clear Lake. Coliform bacteria reside in the intestines of warm-blooded creatures, which include humans, livestock, birds, raccoons, rabbits, deer, and many types of pets. All of these creatures are potential sources of the bacteria that have been found in Clear Lake. Steps that could lead to the reduction of bacterial populations in Clear Lake include the following: controlling animal wastes in the watershed; addressing storm drain, sanitary, and water management systems; addressing septic systems; and reducing the resuspension of lake sediments. One vital practice in limiting bacteria inputs is picking up after pets, which is currently required by a Clear Lake city ordinance.

     Now that the lake and it’s watershed have been studied to determine the present water quality, the next step is to decide which restoration options are feasible to implement. Restoration projects are divided into three groups: rural watershed, urban watershed, and lake and marsh. Local leaders will meet with water quality experts and researchers to put together a plan of restoration activities for the lake, the rural areas of the watershed, and the urban areas of the watershed. This plan will then be presented to the public for feedback. After the public has voiced its opinion, a final report for the restoration of Clear Lake will be written. The finals steps will then be to implement the restoration activities, and to monitor their effectiveness. The projected cost of the restoration project is $16 million dollars. The amount of revenue Clear Lake currently provides to northern Iowa annually is $60 million.