See the Creek Walk Slide Show.

Aerial photos (like the one above) show that the Pattee Canyon watershed has changed dramatically over the last fifty years. Residential development, timber harvests and roads impact the creek's water quality, flows and plants and animals living in and near the creek.

Roads have a large impact on streams.  The soil on a road becomes very compacted and plants have difficulty taking root.  Hence, roads are often susceptible to erosion because there are no plants to hold the soil in place.  When roads erode into a stream, they can have dramatic impacts.  For instance, the sediments can cover pebbles and rocks on the stream bottom, eliminating spawning habitat for fish.  If the road is right next to a stream, the lack of trees to shade the creek may increase temperature; warmer temperatures are often stressful to creek life.

Culverts are large metal tubes placed under a road that allows a stream to flow underneath the road.  This allows a road to cross a stream for much less cost than building a bridge. The dirt packed around the culvert however, often erodes into the stream during high flows.  Culverts may also prevent the movement of fish up the creek because water flows so quickly through the culvert fish cannot swim against the current.  

There have been a large number of timber sales in Pattee Canyon over the last fifty years. The clear cuts on Mount Deanstone are visible from the Missoula valley; however, there are other clear cuts that are not visible from the city. As more trees are cut, more water and sediment wash off the land into the stream.  When sediment yield to the stream rises much above the natural level, the sediment can be harmful to stream life (choking fish, aquatic insects; smothering fish eggs). We can lessen the impacts of forestry practices, by leaving a larger strip of trees along the stream (this is called a buffer zone).  In addition, the area of tree harvesting and roads must be kept below about 10% of the watershed and allowed to recover before more cutting is done.

Residential areas pose additional threats since residents tend to channelize (straighten) creeks and remove most, if not all, of the streamside vegetation.  When a creek is channeled and much of its streamside vegetation is removed, there is a high probability of flooding and bank erosion during spring high flow.  Flooding has occurred in Pattee Creek (see slide show) and is a major concern to Pattee Creek residents.  Many Pattee Creek residences also have inadequate septic systems that may affect the creek.  Systems may leak sewage into the groundwater allowing harmful bacteria to enter drinking water and nutrients to reach the creek.

Cumulative Effects:

While studying the impacts of human development and resource extraction on specific watersheds, we must remember that one activity studied individually may have little effect on the watershed, but the cumulative effect of inadequate sewage systems, clear cutting, stream diversions and culverts can add up to major detrimental effects that impact the watershed. This is why it is important to study every way the stream has changed over the years, compare the watershed to healthier watesheds within the same bioregion and from that data attempt to implement a plan aimed at sustaining the health and balance of the Pattee Canyon watershed.