Studies & Surveys
Phosphorus
Phosphorus: the hidden driver
Phosphorus is the main nutrient that fuels algae growth
Higgins Lake is naturally low in nutrients, so small increases matter
Phosphorus often rises before visible problems appear
Why clear water can be misleading
- Invasive quagga mussel filter algae from the water
- Filtering removes phosphorus-fed algae → water looks clearer
- Phosphorus is not removed from the lake
- It is stored in mussel waste and bodies and settles on the lake bottom.
- This can lead to near-shore algae and weed growth even while open water stays clear
Where phosphorus comes from around Higgins Lake
Septic systems
Septic systems
Even properly working systems release small amounts of phosphorus, and nearly all homes rely on septic rather than sewer systems. Aging or failing systems release much more
and can be carried by nutrients that move through groundwater to the lake.
Runoff and fertilizers
Runoff and fertilizers
Lawn fertilizers, soil erosion, leaves, and grass clippings, along with heavy rain events, create runoffs that leak into the lake and streams.
Internal nutrient recycling
Internal nutrient recycling
Invasive quagga mussels collect phosphorus in their bodies and release phosphorus to the sediments. When the mussels die, they release large amounts of phosphorus to the sediments. When the mussels die, they release large amounts of phosphorus that can fuel rapid algae growth.
Why monitoring phosphorus matters
- Explains changes in algae occurrence
- Explains why water clarity alone can be misleading
- Protects shorelines, recreation, and property values
- Supports informed decisions about septic care and land practices