I currently live  by Lake Tahoe in Placer County, California. We have the highest annual snowfall of any county in the lower 48 US states.  After living here this month, I don’t doubt it!  According to one of the local ski resorts, Alpine Meadows, the snowstorms of November 2010 have produced record amounts of snow, 6 feet in 6 days!

Over the course of the storm I watched as enormous plows cleared the roads. Later huge snow-blowing vehicles would come widen the road. And lastly, after the storm, bulldozers cleared the built up banks and drifts to get the roads, almost, back to normal.

I started thinking about how unsustainable this method of snow removal is.  Not only are there emissions associated with the operation of massive equipment, but also contamination of the snow from salt and sand, road-side litter, and automotive pollutants.  Lastly, snow removal is hugely expensive! In Placer County 15-20% of the annual road maintenance budget is spent on snow and ice control.  I decided to do some research into solutions that incorporate sustainable snow removal and possible reuse in areas that receive a large amount of snow precipitation.

The most inspirational methods came from the City of Sapporo, the capital of the northern-most Japanese island of Hokkaido.  Sustainable urban development is at the core of Sapporo’s city planning, and as a city with approximately 20 feet of snow accumulation and a population of 1.9 million people, it is vital that snow removal be part of the city’s sustainable initiatives.

Sapporo minimizes its dependence on snow-related transportation using heated roadways, centralized and local snow disposal facilities, and snow melting systems.  In addition to a large, underground snow-melting tank, Sapporo has five Snow Flowing Gutters, which use river water and reclaimed water to move and melt snow.

This gutter system particularly intrigued me.  Basically, there are grates at the sidewalk’s edge.  Citizens then dispose of the snow in front of their residence and businesses into the gutters.  The flowing water carries the snow to a treatment plant or to a snow-melting tank.  If reclaimed wastewater is used, the temperature of the flowing water is generally about 50 degrees Fahrenheit, which melts the snow.  This system eliminates the use of large mechanical vehicles and the emissions and cost associated with them, reduces the need to chemically melt snow, and empowers the city’s inhabitants to help with snow removal.  However, the system is still centralized and the reclaimed water and melted snow are still being carried through pipes off-site.

I wonder how this system could be further developed. Instead of just transporting and disposing of the snow in an innovative way, what if the water from the melted snow could be reused or treated entirely on site in order to reduce stormwater runoff and recharge the groundwater?  Designers could use low-impact design stormwater or rainwater harvesting principles to the melted snow.

This way snow removal would become part of a circular water system.  In areas with considerable snow accumulation, geothermal heat pumps or energy from renewable sources such as photovoltaic panels or a small-scale wind turbine could heat sidewalks or roadways.  In areas with only moderate snowfall this step could be eliminated.  Remaining snow would be shoveled into grates, bringing it underground where it could mix with reclaimed “waste” water to aid in melting the snow.  Finally, all of the water from the premises (wastewater, graywater, stormwater AND snow-melt) could be handled using any variety of sustainable design strategies.   In this context, I particularly like a system similar to that designed by Sherwood Engineers and CMG Landscape Architecture for Old Mint Plaza, where the combined water could infiltrate to the groundwater table.

Over the last two weeks of researching the concept of sustainable snow removal, I have come across many concepts that are in use, and I’ve started to think of new ways to manipulate these systems.  I am truly excited about the idea and I would love to hear about any methods that readers have heard of or thought about!

Tags: Sapporo, Snow Removal
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