Salt in a freshwater stream

Salt in a freshwater stream

Chloride (salt), is a problem in many freshwater streams in areas where the winters include snow and ice.  To keep our roads and sidewalks safe for walking and driving we use salt to melt the snow and ice. Unfortunately many of the creatures that call the creek home are not able to survive when their freshwater stream is inundated with salty runoff after winter storms. This problem is also connected to the amount of development in a watershed, as more roads, parking lots and sidewalks are built we must aplly more salt to keep these surfaces clear during winter weather. This is, at first gance, a hard problem to address because it is imperative that roads and sidewalks are safe for people in cars and on foot. 

That said, we have been investigating best management practices that can be implemented to ensure that the application of salt in the watershed is judicious and takes advantage of advanced solutions to this issue. Here are some of the approaches that we are currently researching: 

• Promoting more shoveling for hire as a good micro-economy for the unemployed or underemployed people that live in the watershed
• Encourage poeple to collect the left over salt off of their driveways and sidewalks before it washes into the creek. They can reuse this and save a little money and reduce the amount of trips to buy more salt. 
• Work with salt trucks to ensure that equipment is properly calibrated and appropriate best management practices, such as turning off the flow of salt at stops, are being observed.
• Sometimes salt is stored in a pile that is exposed to the weather, this allows for a highly concentrated flow of salt to find its way into a storm drain and from there into Kiefer Creek. We will be on the lookout for opportunities to help watershed stakeholders implement sound salt storage practices.  
• Brine systems that apply liquid salt prior to the weather event, preventing the precipitation from freezing to the road surface. This may require subsequent plowing and additional salt application depending on the severity of the storm. However it has been reported that this system has been a cost savings for local municipalities that have invested in this upgrade.

It is also important to think about how the salt gets from the paved surface into Kiefer Creek. Often times the path that runoff takes carries it through a number of channels and even water bodies like detention ponds, before it finally makes its way into Kiefer Creek. Sometimes the stormwater pipe connects directly to the creek. It may be possible to better understand the course of these drainage patterns in terms of their ability to mitigate the intensity of the salt pulse.

Where the connection is a fairly direct linkage of a large impervious surface to the stream channel it may be worthwhile to consider the integration of permeable pavers and a buffered channel to provide more infiltration and mitigation of the saltwater pulse. In an area where a subdivision drains into a paved surface drainage channel there may be the opportunity to reconstitute these riparian corridors to provide increased infiltration. Many of the solutions that are good for the watershed in general are also beneficial to recuding the impacts from chloride on Kiefer Creek. 

This website and other efforts related to the Kiefer Creek Restoration Project are partially funded by the Environmental Protection Agency Region 7 through the Missouri Department of Natural Resources, under Section 319 of the Clean Water Act. MoDNR Subgrant G11-NPS-21.