Lake Petersburg Homeowners Association
Diagnosis of the Lake Information From their website:
1400 ACRES WATERSHED
14 MILES SHORELINE
190.7 ACRES UNDER WATER
12 MILES OF ROADS
24 FT AVERAGE DEPTH
65 FT WATER DEPTH AT DAM
have taken the liberty to copy a few paragraphs from the Lake Petersburg website
) in order to comment on what our aeration systems can do for your lake.
Please spend the time to look it over and you will be glad you did. The next generations can have a
lake that is always new in water quality...free of algae, pondweeds and grass
carp that will ruin it for all species of fish if you continue to use that
method of fighting the problem.
We know of several ten to two hundred acre lakes that
have been ruined with grass carp. Please discontinue stocking them
in the lake. Sometimes those so-called hybrid grass carp reproduce and
become populated to the point that they eat every last bit of vegetation in the
lake, thus eliminating the habitat that more desirable species need to
propagate. After that happens their is no return to
a balanced ecology.
WATER CLARITY UPDATE (Information submitted by
We reported in the Summer Newsletter on the clarity of Lake Petersburg.
Sampling has occurred twice a month, May through October. The graph shows how
deep, on average, the Secchi disk could be seen each month (the higher the
number the more clear the water). The lack of rainfall would have caused
nutrients to flow out of the lake. The drought has influenced the clarity
readings because more nutrients have been trapped in the lake accounting for
lower clarity readings in October.
The yearly average water clarity was higher this
year than the past two years! The average annual Secchi disk reading was: 2003 -
50.8 inches, 2004 - 64.3 inches, and 2005 - 68.5 inches. The clarity of our lake
is moving in the right direction.
Water clarity is influenced by nutrients and
sediment. The more sediment there is in the water the lower the clarity.
Likewise: with more nutrients in the water, there is more plankton (algae) and
you have lower water clarity. The Association has and is taking measures to
reduce sediment and nutrients.
Lake Petersburg at this stage in its life is fortunate not to have very much
sediment flowing into the lake. The Association has taken measures to reduce
sediment input from the watershed through no-till farming and planting grass
waterways on Association property and paying for grass waterways on property
that we do not own. The development of the back nine holes at Shambolee Golf
Course reduced the amount of sediment coming off what was formerly farmed land.
Most of the areas on the lake that can be developed have been and therefore
erosion from construction sites is minimal. [Because golf courses are
highly fertilized, there may be an increase in the amount of nutrients entering
the lake. However, the non-biological erosion should be greatly improved.]
The dredging project will remove sediment from
coves and bays. A sediment survey documented the amount of sediment. The areas
most impacted by sediment will be dredged. Those areas will be dredged to a
depth of 7 feet or the original bottom which ever is less. A map of the areas to
be dredged is available at the Lake Office. Removal of the sediment will also
reduce the amount of the nutrient phosphorus in the lake. Phosphorus binds to
clay particles in the sediment.
Nutrient Reduction and Management
Measures have also been taken to reduce nutrient input. The soil conservation
practices mentioned above also reduces nutrient input from the farmland in the
watershed. The retention ponds on the golf course process nutrients before they
enter the lake. The sewer significantly reduced nutrients entering the lake.
Another source of nutrients is lawn fertilizers.
Judicious use of lawn fertilizers is encouraged. Before fertilizing your lawn
have the soil tested. You may be putting more fertilizer on your lawn than it
needs. It will also save you money. Slow-release fertilizers are recommended for
long-term lawn care because they make the nutrients available consistent with
plant needs and will not leach below the root zone.
Leaves and grass contain nutrients. Remember the
fertilizer you put on your lawn? It ends up in the leaves of the grass. Do not
dispose of grass clippings and leaves in the lake because this adds unneeded
nutrients into the lake.
The last 10 years you have not seen many rooted
aquatic plants (seaweed) in the lake. The reason is the grass carp eat those plants. If you
have no rooted aquatic plants only the algae will take up the nutrients. This
reduces the water clarity. Rooted aquatic plants take up nutrients too. If you
have some rooted aquatic plants it will reduce the amount of algae. The
Association is working to try and reach a balance between the amount of rooted
aquatic plants and algae. We hope to have just enough grass carp in the lake to
prevent the rooted aquatic plants from becoming a nuisance yet use up some of
those nutrients and provide habitat for young fish like the red-eared sunfish.
PETERSBURG Lake Recovery
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