Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants What's worse?

Fishhead -- As I see it there are not easy answers for your situation. I tend to be a realist. You are not going to like my answer but read it anyway because it contains the basic facts of pond's life history. Nature determines or dictates these facts; not I. We pondowners have to deal with them and are thus called pond owners/managers.

This is a brief summary of a lot of complex occurrences that affect the aging of a pond over time.

All ponds have a usefull life span similar to humans and all animals. As soon as a pond fills with water, "mother nature" begins to fill it back up with solids such as silt/soil, and dead organic materials that are produced within the pond and also come in externally such as leaves from trees.

Nutrient (fertilizer) inputs speed the internal growth rate of plant material that eventually dies and settles in the pond. Accumulation of dead organics are primarily responsible for the muck buildup and filling in of the pond. Soil from watershed runoff is the other main component of the fill material.

As a pond ages nutrient accumulation continues and overall water quality gradually decreases. First signs of this water quality deterioration are fish kills (summer or winter). Fish kills become more frequent as more aging occurs, water quality decreases and organic accumulations continue to increase.

AS pond aging continues blue-green algae surface films or blooms become more and more frequent during the warmest months. Often associated with this nutrient enrichment (pre or post bluegreen blooms) are growths or blooms of duckweed and water meal. Nutrient ratios (nitrogen & phosphorus) and amount of dissolved organics determine which type of nutrient enrichment type of indicator plant is currently "blooming". Ponds with these situations are called hypereutrophic and getting old in the life span scale of water bodies.

Severly hypereutrophic ponds have a hard time getting quality sport fish to survive for long periods due to periodic oxygen shortages from the decay of the frequent plant blooms from the accumulated and continual nutrient enrichment. Ponds in hypereutrophic conditions are often shallow and close to , deep wetland, wetland, or swamp status. Things can be done to prolong the "life" of these aged ponds but the methods are usually costly and only a temorary band-aid the the further aging and filling-in process. Ther are those pond and lake managers that specialize in methods that delay the aging process and slowing it down.

When a pond gets to hypereutrophic status I usually recommend redigging or rebuilding; starting over. Dredge or remove all the accumulated organic nutrient containing sludge. Reshape and or deepen the pond. While this is being done, the high-input of nutrient sources should eliminated or minimized so the pond has a longer life span the second time around.

How soon a pond or lake needs to be rebuilt is dependent on how it was originally designed (depths, shape, slopes), how it has been managed from the beginning and how fast the nutrients have accumulated. Another thing that affects how soon a pond needs to be rebuilt is how much aggravation, frustration, and water quality deterioration will the owner tolerate during an annual pond cycle. Cost can be another big factor. A pond or lake can be an asset or a liability / detraction.
Basically, I think you should start thinking about rebuilding your pond. Get some estimaes and see if it is within your financial ability. If you don't do it the next owner will have to rebuild if they do not want continual headaches trying to maintain a "nice" relatively trouble free pond. Many pondowners in my area are rebuilding their ponds after 25 to 35 yrs. This is primarily due to poor original design and improper management during the pond's early & mid life history. One contractor in my area does as many pond rebuilds as new pond constructions.

I may come back to this later and add more as I reflect on it.