Yarmouth, Nova Scotia.
If you go back just a few years ago this site was part of Yarmouth’s wetlands and Broad Brook, the central drainage basin of our town, ran through it. The wetland was filled and the brook placed in a pipe. TREPA made a good case, we thought, for alternative sites that would leave the brook and wetland in its natural state providing the values that wetlands serve – like buffering to flooding and a conduit for water to get back to the ground water system.
This is a lesson in impermeable surfaces. Paving sheds over 95 percent of the water that falls on it. Thus, it pushes water quickly into the natural drainage system and overwhelms it causing downstream flooding. We might see this photo as just reward. The runoff from this site and other paved areas has so completely overtaken the natural drainage system that even they can’t drain and have become surface storage areas – not a part of the original engineering scenario to be sure.
Fortunately, the lower Broad Brook wetlands, south of the golf course, have not been developed and are now fully flooded with no damage to property or homes. TREPA has requested of the municipality that these wetlands and bogs be protected.
Yes it rained a lot, but –
What percentage of the Tusket River Water Shed Area has been clear cut and poisoned with herbicides with the approval of the Province of Nova Scotia? Barren forests don’t hold back rain fall as long as real living forests can.
Good point Doug. Runoff from forest is 6-20 percent depending on soil type and slope, among other things. Our forests have pretty thin and impermeable soils so once cut the runoff increases quite a bit. Clear cutting destroys not only the forest but also alters the nature of the soil and its humus content. Total cost accounting is certainly missing.