Headwater Drainage Features

Headwater drainage features (HDFs) are the small stream, swale, and wetland features that capture water and transport it to larger streams and rivers.

Some HDFs do not flow all the time, but may flow after rainfall or snowmelt, or due to seasonally high groundwater levels.

HDFs are important! When left in their natural state, these features have many functions — they help to reduce stream flooding, purify water, and provide food and habitat for fish and wildlife.

this small stream on agricultural land is an example of a headwater drainage feature or HDF

Urbanization Degrades HDFs

Ecologists are concerned that urbanization can cause degradation of HDFs.

Their small size and the fact that they do not always flow year-round makes HDFs vulnerable to impacts such as piping, channelization, flow diversion, grade lowering, and realignment.

Headland drainage features or HDFs include small streams and wetlands

Scientific evidence suggests that HDFs are important sources of food, sediment, nutrients, and flow to downstream aquatic systems. They also provide water quality, storage, and attenuation functions.

To help guide management actions needed to protect HDFs, TRCA and its partners developed a resource: Evaluation, Classification and Management of Headwater Drainage Features Guidelines.

Select the thumbnail below to download the guidelines

Guidelines for Evaluation Classification and Management of Headwater Drainage Features

What Can You Do to Help?

  • Leave HDFs in their natural, undisturbed state.
  • Leave vegetation within and around HDFs, maintain existing drainage flow, and keep livestock away.
  • Maintain the vegetation surrounding the streams to improve the quality of water and food carried downstream and to remove nutrients and sediment.

HDF Resources

Click to Open Library




Technical Training

The Ontario Stream Assessment Protocol (OSAP) course is designed to train and certify users in a variety of standardized stream assessment techniques for evaluating habitat, benthos, and fish communities in Ontario’s wadeable streams.



TRCA Watershed Planning and Ecosystem Science: wpes@trca.ca