Habitat Loss

The Issue

Everyone needs a home! In order for our local waterways to support a healthy aquatic community, we need diverse habitats for them to live in. Different fish and bugs need different habitats. Some like fast flowing water with rocks or riffles while others need deep pools, overhanging vegetation, small gravel beds for spawning or backwater areas to take refuge in. Fish need to be able to freely move upstream and downstream to find food, mates and safe places to lay their eggs. Most of the macroinvertebrates or bugs in the stream have an adult stage in the air and require good vegetation along the shoreline. All of these physical components together make up the habitat of a site. 

Some of the biggest water quality challenges we face in urban streams is the loss and fragmentation of habitat. Most development in the last 30 years shunts stormwater to local streams via storm sewer systems. The stream flows go up and down quickly, causing erosion over time.  

The problem with erosion is two-fold. First, when the shoreline or stream bank erodes, riparian habitat is lost. Second, the eroded sediment moves downstream and builds up in slow parts of the stream system. This sediment covers the substrate on the bottom of the stream filling in spaces between the rocks and gravel where small invertebrates make their homes.  

Streams are fragmented by obvious things like dams, but also by poorly designed culverts at road crossings or on-line detention systems. Dams and other infrastructure that cut off part of a waterway cause a great loss of habitat, especially for migratory fish.  

Stream and riparian habitats are further impacted by development in the floodplain, removal of native vegetation from streambanks and leaving no place for floodwaters to spread out. 

Eroded shoreline around a detention pond

Shallow-rooted turf grass cannot hold the soil in place, so the shoreline erodes over time.

Hammel Woods Dam

Dams prevent fish from moving freely through the river. They also cause sediment to accumulate upstream of the dam, which causes further habitat loss.


  • Restoring native vegetation along the streambanks and riparian areas will help slow water down and provide habitat for adult stages of aquatic insects – they are the base of the food chain for the fish that live in our streams. 
    • If you live along a local stream, create a buffer of native plants
    • Support your community’s efforts to convert turf to native buffers on public lands.
  • Help reduce stormwater runoff by building a rain garden or incorporating deep-rooted, native plants in your yard. 
  • Support local dam removal projects to allow our streams to flow free.
Native flowers in bloom around detention pond

Detention basins and streams with a strip of native plants along the shoreline have plenty of riparian habitat for aquatic insects like dragonflies. The deep-rooted native plants also prevent shoreline erosion.

Boulders for riffles in stream restoration project

An in-progress stream restoration project that will create new habitat. The cobbles will form riffles and the embedded root wads create places for fish to hide, rest, and breed.

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