Our Country Lane
City Farmer's Country Lane Reduces Rain Water Discharge to Vancouver's Storm Sewers
August 4, 2003
Our Country Lane is in! As we reported a year ago, City Farmer's demonstration garden was chosen as one of three pilot sites for this alternative to the growing number of asphalt lanes. The "country lane" uses materials that allow rainwater to infiltrate into the ground while providing a durable surface for vehicles to drive on. The lane calms traffic, is aesthetically pleasing and more environmentally responsible. The three demo sites were chosen because of strong community support and commitment by residents to help maintain and promote the concept. The Country Lane project is a joint initiative from the City of Vancouver's Streets Design Branch and Greenways. Greenways is responsible for the greening of pedestrian routes throughout the city. They also initiate public art and other environmental considerations on the "green ways".
The City Farmer country lane is unique among the three sites because the lane was short and narrow, so it was constructed differently. Here are the steps that streets engineer, Wally Konowalchuk, Greenways landscape designer, David Yurkovich and crew took to install our lane.
First they excavated. Typically they dig down to about four inches and then they check the subgrade soil. In our case, the subgrade was not up to snuff, so they had to dig down to about 18 inches. Next they fill the excavated area with gravel to make a strong subgrade so that garbage trucks and fire engines can roll up the lane without sinking. Then comes the structural soil. This is a mixture of 70% aggregate (3/4" rock) material mixed with 30% sandy soil. The rocks interlock to form a strong base and the sandy soil mix provides good drainage and promotes grass growth.
The four to six inch base of structural soil is then overlaid with Golpla also called structural grass. These plastic grids function to support vehicle weights, help to distribute the load of vehicles, prevent soil and grass root compaction and soil rutting. Some of the cells of the Golpla are filled with topsoil and grass is planted, others are filled with gravel. The topsoil provides a medium for grass growth, provides water retention during dry periods and allows drainage during storm events. Instead of the two concrete driving strips that the other lanes have, our strips are just Golpla filled with gravel. A grassy strip runs down the center of the two strips and grassy areas are also planted along the edges of the lane.
Along the sides of the country lane, especially in "connector" sites where the lane links with a neighbour's driveway or the apartment building parking lot, broken concrete was laid. The City tore up a sidewalk, excavated the pieces and brought them to the lane site. There they broke up the pieces and laid them in place atop a base of gravel with a top layer of sand. Top soil was then applied between the concrete and was planted with grass. A few of the broken pieces of sidewalk were also laid decoratively down the middle of the lane in the grassy strip. Pavers were laid at the top of the lane that meets the City Farmer driveway and a small amount of asphalt was poured in a couple of other connector sites, creating asphalt aprons.
An area alongside the apartment building was landscaped with boulders, top soil and some drainage to allow for additional water absorption. This fall, David Yurkovich will complete the landscaping, planting mostly native, waterwise plants and some ferns in the shady areas.
The country lane benefits are many. First they are greener and more attractive back lanes and they help to reduce vehicle speeds. The environmental benefits include reduced flow into the City's sewer system; natural drainage that replenishes the groundwater; natural filtration and improved air quality.
Since the lane has been installed, more and more people are walking up and down it. Previously, pedestrians would come into our garden via the driveway, now they prefer the lane. It is very inviting. We've had many people, including the fire department(!) visit our garden for the first time because they noticed the lane as they were walking or driving by and were drawn in. We hope to have a Country Lane street sign installed that should invite more people to walk up the lane. The lane leads up to our beautiful cob garden shed and outdoor oven that is nearing completion.