Perhaps you’ve just moved to a new home with an earth pond that’s been left on its own for too long. Or maybe you’ve had an earth pond for a while now and you do all the necessary pond upkeep tasks regularly. Whatever the case, and no matter how diligent a pondkeeper you are, nature can sometimes get the best of your pond. Here are some tips and tricks for diagnosing the cause of common earth pond problems, and fixing them.
Algae
Problem: Inadequate exchange of fresh water.
Solution: Increase inflow.
Problem: Pond too shallow and/or warm.
Solution: Dredge deeper; increase flow.
Problem: Excessive nutrients flowing into pond.
Solution: Eliminate nutrient inflow; use biological methods to decompose or eliminate nutrients; use aeration.
Aquatic Weeds, Emergent
Problem: Taking over pond edges, basin.
Solution: Use biological methods; manually remove weeds; dredge; draw down.
Aquatic Weeds, Submerged
Problem: Taking over pond.
Solution: Use biological methods; manually remove weeds; dredge; draw down.
Embankment Erosion
Problem: Slope too steep; poor soils.
Solution: Reseed and mulch; sod; riprap; add fill to flatten slope.
Low Water Level
Problem: Leaks in porous soil, ledge or piping.
Solution: Seal basin with clay or artificial liner; repair or eliminate piping.
Problem: Inadequate inflow; embankment and/or spillway too high.
Solution: Increase inflow; improve natural runoff; adjust spillway and/or embankment level.
Problem: Holes in basin or embankment caused by muskrats.
Solution: Trap muskrats.
Overtopping; Flooding
Problem: Frozen outlet, spillway blocked by ice.
Solution: Thaw pipe, reopen spillway, repair outlet.
Problem: Watershed drainage too much for spillway capacity.
Solution: Enlarge outlet pipe; enlarge spillway; divert inflow; install emergency spillway.
Overtopping
Problem: Outlet pipe or spillway blocked by debris or beavers.
Solution: Clean pipe or spillway; add trash guard to outlet; trap beavers; install anti-beaver flumes; consult game department officer for assistance.
Siltation; Sediment
Problem: Erosion or inflow stream; erosion of watershed.
Solution: Prevent erosion of inflow stream/watershed.
Stagnant Water
Problem: Inadequate exchange of fresh water, basin too shallow.
Solution: Increase inflow; dredge basin; aeration.
Fishkill
Problem: Inadequate dissolved oxygen.
Solution: Increase inflow; aeration; reduce fish population; eliminate dead vegetation.
Problem: Overheated water.
Solution: Add cooler water; create shade; deepen pond.
Problem: Toxic chemicals.
Solution: Test water.
Problem: Disease.
Solution: Consult fisheries biologist.
Fish Disappear
Problem: Herons; kingfishers.
Solution: Use scare-away devices; netting; do not shoot; protected species.
Problem: Leaving via spillway.
Solution: Screen outlet stream.
For more information about maintaining an earth pond, see An Earth Pond Maintenance Guide.
