DESTRUCTION OF HIGH ELEVATION HYDROLOGY

DESTRUCTION OF HIGH ELEVATION HYDROLOGY

I am a stormwater hydrologist and Principal of Watershed Consulting Associates in Waitsfield, Vt. My firm specializes in modeling, designing, and permitting stormwater management systems. I have conduct ed water quality research and designed stormwater systems in high elevation watersheds. I have also closely reviewed stormwater designs and permit applications for the Sheffield Wind, Kingdom Community Wind, and Deerfield Wind Expansion projects.

High elevation areas of Vermont include numerous seemingly insignificant seeps, where groundwater 002es from the subsurface and begins to concentrate to form discrete stream channels. These headwater streams and wetland areas are the birthplace of our surface water resources. They constitute the greatest percentage of total stream length in an undisturbed river system, but are also mostly unmapped. They are vitally important for providing clean and cold water, habitat, and flood control; however, they can only provide such services if they are protected from disturbance.

With continued development in Vermont and our nation, conversion of undeveloped pervious surfaces to impervious and the potential impact to the hydrological water balance from climate change, protection of these headwater resources is a very wise investment for a sustainable future.

We now know the best way to keep pollution out of our surface waters and to preserve stream hydrology is to control the overall volume of stormwater being generated on a developed site, by designing sites to replicate natural conditions. Current State stormwater regulation was not developed on this premise.

Preserving high elevation hydrology cannot be successful by playing defense; the approach mu st be holistic and include minimizing the project footprint as the primary consideration.

Lowell, Sheffield, Deerfield, and Georgia Mountain will result in the creation of 81 acres of new impervious surface, not considering the acres of newly exposed bedrock. This is more than eight Williston Wal-Mart facilities combined.

The only solution to water quality protection is to downscale the infrastructure required for these projects. Monitoring, before and after development, is an absolutely key component to a successful strategy.

This monitoring plan must allow for instream testing on the project site, where the small headwater areas are located and at the points of stormwater discharge, not just at locations a mile or more downstream of the project site, as was done in Lowell and Sheffield.

Many acres of roads have been constructed to service the Lowell and Sheffield projects. Shortly after construction, these roadways have compacted to form an impervious surface akin to pavement.

I have repeatedly expressed my concerns to ANR on this issue but have been disregarded. If precipitation events intensify, as predicted, with the onset of climate change, the inaccurate modeling of runoff from these projects will result in even more water quality impact and downstream flooding impacts.

—Andres Torizzo