Aquatic Plant and Algae Management

Restore clear, healthy, usable water with targeted plant and algae control and long term management.

Aquatic plant management

Selective control of nuisance and invasive plants

Aquatic plants play an important role in supporting fish populations, stabilizing shorelines, and improving water quality, but excessive growth can cause significant problems. Invasive or nuisance species like Eurasian watermilfoil, curlyleaf pondweed and flowering rush can quickly overrun a lake, reservoir or pond, outcompeting native plants, reducing open water, and clogging drainage systems. Floating vegetation like duckweed, azolla and watermeal can block sunlight from reaching submerged plants and reduce oxygen levels, further degrading water quality. These tiny floating plants can cover a pond quickly. They respond best to early season treatment combined with cutting nutrients.

Our programs begin with a detailed waterbody assessment to identify problem species and determine the most effective control strategy. Depending on the situation, we use EPA registered aquatic herbicides to selectively control invasive plants while preserving native and beneficial vegetation.

Some aquatic products carry a waiting period before treated water can be used for irrigation. We choose products with no irrigation restriction where possible and schedule any holding time around your irrigation calendar.

Milfoil growing thick under the surface of a pond in fall

Before and after

Before and after results

Real ponds we manage, photographed before and after.

Pond with floating mats of aquatic weeds before restoration

The same pond with open, clear water after restoration

BeforeAfterDrag to compare

Aquatic weeds

Thick clumps of a harmful algae bloom on a pond surface before restoration

The same water, clear of the bloom after restoration

BeforeAfterDrag to compare

Harmful algae bloom

Pond covered in filamentous algae before treatment

BeforeAfterDrag to compare

Filamentous algae

From survey to plan

A management plan built for your lake

01 / 03

Map where plants grow

A hydroacoustic survey measures plant biovolume across the entire lake, showing where growth is dense and where the bottom is clear.

ClearDense

02 / 03

Identify what is growing

Point intercept sampling identifies the species at each location. In this example lake, curlyleaf pondweed dominates, with patches of large leaf pondweed, a few sago pondweed, a few Eurasian watermilfoil sites and one northern arrowhead.

Curlyleaf pondweedLarge leaf pondweedSago pondweedEurasian watermilfoilNorthern arrowhead

03 / 03

A plan tailored to this lake

With both maps in hand, we build a management plan around what is actually growing and where.

Focus control on nuisance and invasive growth, starting with the Eurasian watermilfoil sites before they spread.
Protect native beds that support fish and wildlife.
Time the work to each species’ growth cycle.
Survey again to measure results and adjust the plan.

Plant species survey points on the example lake

Example · Plant biovolume

Plant biovolume

ClearDense

Species

Curlyleaf pondweedLarge leaf pondweedSago pondweedEurasian watermilfoilNorthern arrowhead

Algae and cyanobacteria

Early detection, targeted treatment, lasting results

While some algae are a natural part of the ecosystem, unchecked growth, especially harmful algal blooms (HABs), can produce toxins, deplete oxygen, and degrade water quality. Cyanobacteria, commonly known as blue green algae, can create toxins that are harmful to people, pets, and wildlife. Filamentous algae and surface scum also reduce clarity, clog intake systems, and create unpleasant odors.

Keep dogs out of water with scum, discoloration or streaks that look like spilled paint until it is tested. Toxic algae can kill a dog quickly. Learn about harmful algae blooms.

We use EPA registered algaecides to control algae with minimal impact on fish and aquatic life. Killing a toxic bloom can release its toxins into the water, so a suspected toxic bloom is tested first and the treatment is planned with that in mind.

To help keep blooms from coming back, we address the root cause: excess nutrients. Our phosphorus inactivation treatments bind phosphorus in the water and sediment so less is left to feed algae.

Proactive management

Early detection through regular surveys

Aquatic plant and algae problems can escalate quickly, so early intervention matters. We take a proactive approach with regular plant surveys, algae identification and vegetation mapping to find issues before they become widespread.

Algae often responds within a few days and most rooted plants within 1 to 2 weeks.