As of right now, the water quality of Spring Brook continues to meet the stingy habitat demands of the native brook trout that live in the stream.  However, all around the watershed are threats that could potentially degrade the stream and jeopardize the trout.  It is important that these threats are revealed and accepted as real problems so that they may be monitored and dealt with in the best way possible.  The following are some of the current or potential threats facing the Spring Brook watershed and its resident wild brook trout.

(1) Development
The populations of Northfield and Dundas continue to grow.  As these communities expand expand, development spills into the surrounding undeveloped tracts of land.  The population of Northfield grew over 15% from 1990 to 2000 (ERsys.com).  The expansion of these cities will bring with it changes in land-use within the Spring Brook watershed.  In 1999, a developer wanted to build a housing complex complete with a golf course right in the riparian area of Spring Brook.  It is developments like these that will be tougher to turn away as the cities grow in population and demand for development increases.

In the past few years alone, there have been developmental changes close to Spring Brook that may have long-term effects on the health of the watershed.  According to Chris Robbins, recent developments like the Menards and Target stores could pave the way for further developments along county road 1, which runs directly through the watershed of Spring Brook.

The general effects of urbanization on trout streams include:

• Erosion from construction sites leading to siltation of the stream
• Impervious surfaces leading to higher streamflow and erosion of streambanks because water runs off instead of soaking into the ground
• Heavy flows from parking lots, driveways creates warmer water temperatures
• Bridges and culverts disrupt the natural stream channel
• Groundwater depletion
  

(2) Cattle Grazing and Agricultural Runoff
Agricultural runoff has been the source of many fish kills.   In 1984 a fish kill occurred at Spring Brook that nearly wiped out the entire population of native brook trout.  Because these trout are wild and native, there is no way to replace the population if it is completely killed off.  The fish kill that occurred at Spring Brook happened after a heavy rain, and it is suspected that pesticides were washed into the stream.  It is also likely that manure from cattle and horses was washed into the stream during this rain event. 

There is good evidence that fencing trout streams off from cattle can increase trout numbers and fish size.  In a study done in Colorado, a stretch of the stream fenced off from cattle displayed less streambank alteration, and estimated trout standing crop was twice that of unfenced sections (Stuber et al., 1985).  A study in done in Montana shows found that the biomass of brown trout was 3.4 times higher in a ungrazed area compared to a grazed section (Marcuson, 1998).  The grazing pressure along Spring Brook is currently not very significant, but is certainly something to consider for management of Spring Brook as a trout habitat.

Another agricultural issue that threatens Spring Brook is the use of drainage tiles.  In the upper portion of the watershed, numerous drainage tiles send water into county ditch 22, which actually serves as the stream channel of Spring Brook through this stretch.  Many farmers insist that the cold water sent to the stream through these drainage tiles is beneficial for the trout, and to an extent they are correct.  However, as former Cannon River Watershed Partnership employee Chris Robbins puts it, "too much drainage can make a stream flashy."  The term flashy applies to the rate at which a streams discharge increases.  Extremely flashy streams can go from a trickle to a raging flow in within minutes.  The drainage tiles in the upper portion of the watershed increase the "flashiness" of Spring Brook, which leads to channel scouring, washing away of trout cover, and extreme flows that are detrimental to trout survival.