8 Common Stormwater Pond Problems (and How To Fix Them)

Stormwater ponds are vital to managing runoff, improving water quality, and protecting downstream waterways. Found on commercial properties, HOAs, and municipal sites, these engineered systems are designed to capture and treat stormwater before it’s released – often holding water year-round, like a retention or wet pond.

But without routine maintenance, stormwater ponds can quickly lose efficiency and develop issues that affect performance, appearance, and compliance. Below are eight common stormwater pond problems, how to identify them, and how to keep your system functioning at its best.

1. Sediment Build-Up

Sediment naturally settles in stormwater ponds over time as runoff carries soil, debris, and pollutants from surrounding areas. Left unchecked, this buildup reduces pond depth, storage capacity, and water quality – often leading to algae growth and clogging.

Warning signs:

• The pond looks shallower or has visible sediment along the edges
• Murky or brown water after storms
• Slower drainage or water standing near inlets/outlets

How to fix it:

• Schedule periodic sediment surveys and inspections
• Remove excess sediment through dredging or vacuum excavation
• Maintain forebays and erosion controls upstream to prevent further accumulation

2. Algae Blooms

Excess nutrients from fertilizers, pet waste, or decaying vegetation can cause algae to grow rapidly in stormwater ponds – especially those that retain standing water.

Why it matters:
Algae blooms can deplete oxygen, produce foul odors, and create an unsightly surface film. Some blooms, like blue-green algae, can even pose health risks to people and pets.

How to fix it:

• Reduce nutrient runoff by managing fertilizer use
• Maintain a healthy vegetative buffer to absorb nutrients
• Add aeration or fountains to circulate water and reduce stagnation
• Remove nutrient-rich sediment when needed

3. Erosion of Pond Banks

Fluctuating water levels, poor vegetation coverage, and wave action can cause erosion along pond banks. Over time, this weakens structural integrity and increases sediment loading.

Warning signs:

• Exposed soil or roots around the shoreline
• Undercutting, slumping, or collapsing edges
• Bare or uneven slopes

How to fix it:

• Stabilize banks with deep-rooted native vegetation
• Install riprap or erosion control matting in problem areas
• Repair eroded sections promptly to prevent further damage

4. Clogged Inlets and Outlets

Healthy flow in and out of the pond is essential for maintaining water quality and preventing flooding. When debris, vegetation, or sediment blocks these structures, pond function declines.

Warning signs:

• Standing water or overflow after rainfall
• Visible debris blocking inlets or outlets
• Uneven pond water levels

How to fix it:

• Clear trash, leaves, and sediment from inlets/outlets after major storms
• Repair or replace damaged trash racks or grates
• Schedule routine inspections of outlet control structures

5. Excessive Aquatic Vegetation

Aquatic plants play an important role in filtering stormwater, but too much growth can choke the system, restrict flow, and create mosquito-friendly conditions.

Warning signs:

• Dense mats of plants on the surface or around edges
• Reduced water circulation
• Odors or signs of decay

How to fix it:

• Manage vegetation with regular seasonal maintenance
• Remove excessive growth mechanically or through approved aquatic treatments
• Maintain nutrient balance and circulation to prevent overgrowth

6. Mosquito Breeding

Stormwater ponds that remain stagnant or collect debris can become mosquito breeding grounds, especially in warmer months.

Warning signs:

• High mosquito activity around the pond
• Stagnant areas or surface scum
• Floating debris or decaying vegetation

How to fix it:

• Improve water movement with aeration or fountains
• Remove floating debris and decaying plant material
• Introduce fish species that feed on mosquito larvae (where appropriate)

7. Structural Damage

Stormwater ponds rely on control structures – such as risers, pipes, and outfalls – to manage water levels. Corrosion, cracking, or blockages can reduce performance or lead to failure.

Warning signs:

• Rusting, cracks, or settlement around outlet structures
• Leaks or inconsistent water levels
• Damaged or missing screens and grates

How to fix it:

• Schedule annual structural inspections
• Repair or replace failing components
• Use durable, corrosion-resistant materials for long-term performance

8. Trash & Debris Accumulation

Stormwater runoff often carries litter, leaves, and other debris into ponds. Without removal, this buildup clogs structures, reduces storage volume, and degrades water quality.

Warning signs:

• Floating debris or scum near inlets/outlets
• Discolored or odorous water
• Reduced water movement after rainfall

How to fix it:

• Implement regular debris removal
• Install trash racks or floating skimmers
• Educate property users about preventing litter runoff

Why Stormwater Pond Maintenance Is Essential

Routine stormwater pond maintenance ensures your system:

• Remains compliant with local and state stormwater regulations
• Protects against flooding, erosion, and costly repairs
• Preserves water quality and pond appearance
• Extends the lifespan of your infrastructure

Whether your pond holds water year-round or drains periodically, professional inspection and upkeep are key to keeping it functioning as designed.

Partner With iSTORMWATER for Stormwater Pond Maintenance

At iSTORMWATER, we provide comprehensive inspection, maintenance, and repair services for stormwater ponds across Maryland, Northern Virginia, Washington, D.C., and Delaware.

Our experts identify and resolve issues like sediment build-up, erosion, algae, and structural wear – keeping your pond clean, compliant, and effective.

Contact iSTORMWATER today to schedule a stormwater pond inspection or learn more about our maintenance programs.

📞 Call us at (410) 231-3455 or 💬 Contact us online.