Project Background
Discussion of Uncertainty
Sources & Acknowlegements

image source: http://www.tol.bc.ca/



Project Background

The Salmon River watershed is the largest watershed in the Township of Langley. It drains an area of 1510 km2 and is over 120 km in length. An abundance of salmonid and non-salmonid fish species live in the Salmon River and it's tributaries. The watershed is an integral part of the natural environment and our daily activities affect the overall health of the watershed. The watershed has also undergone significant land use changes over the past 50 years, moving towards more and smaller farms and larger urban developments. The Township of Langley has also taken great strides towards sustainability and good stewardship of their natural resources, which at times is at odds with the development taking place.

The Salmon River originates in a low-lying area; a significant contrast to the region's mountain streams. Fed by springs from the Hopington aquifer and surface runoff, the headwaters of the Salmon River are located in prime lands for agriculture and development. This places important fish habitat at risk, and makes its protection a challenging task. This project aims to quantify locations that are at risk for contributing nutrients to the water sources. Nutrients can have severe impacts upon surface waters and the biota it supports. In particular, nitrate can be toxic to fish, and contribute algal blooms and eutrophication. Other nutrients (phosphorus, ammonia and nitrite) can also contribute to eutrophication, which leads to depleted dissolved oxygen, reduced biodiviersity, fish kills, and many other impacts.


The most common pathway for nutrients to enter a surface water is by surface run off from agricultural areas, where nutrient sources such as manure and fertilizer are located. If the property drains into a surface water body, there is the potential for contamination of the surface water by nutrients in the run off. Therefore, critical areas are those that have the potential for run off draining into surface water and are also agricultural lands. This project aims to quantify these regions, and identify trends in land use over time from 1966 to 2001. These aims were met by determining the slope of the watershed, comparing land use over the study time period, identifying areas that have changed land use, and combining this information to determine potential "hot spots" for nutrient contamination by surface run off.

To begin the project, land use data from three different time periods (1966, 1986, and 2001) was collected and formed the basis of the analysis. Click the map icon below for a map depicting the land use for each time period.

Land Use in the Salmon River Watershed

Note: This project also includes a Visual MODFLOW groundwater model to visualize where contaminated surface water would move to in the subsurface from the identified "hot spots". However, results for this component are not yet available and not presented in this website.