The EAH is one of the highest quality unprotected natural resource sites in Eugene. It is a
40-acre parcel of forested land in pristine and undisturbed condition. The land is contiguous
with the City’s Amazon Headwaters Open Space and the Ridgeline Trail System on the south
end, making it a high quality site for supporting native flora and fauna, including rare species
known to exist in the area.
The EAH has a wide range of natural resource values, some of which are reflected in the Natural
Resources Inventory. The site has the highest Wildlife Habitat Assessment ranking in the city
(66-68 points). The site contains 2,800 feet of waterways and approximately three acres of
wetlands. Stormwater Management Benefits The EAH area is a unique site in terms of stormwater management. In its current natural state,
this land provides a perpetual stream of benefits to the city by controlling stormwater. The EAH
is the final stretch of natural forested land in the South Eugene drainage and contributes
significantly to reducing stream flows and erosion from heavy rainfalls. Hundreds of acres of
forested land on the north flank of Spencer Butte buffer and mitigate stormwater that otherwise
would wash down into the Amazon Creek, causing flood conditions on a regular basis. Forests are ideal stormwater management systems. Trees capture and slow rainfall in their
leaves and branches. Roots from trees and understory plants provide moisture pathways for
water absorption. The forest duff absorbs and filters rainfall and facilitates soil absorption and
groundwater recharging. Very little rainwater runs off the surface of a mature, undisturbed
forest. Instead, water percolates through the ground, taking weeks or months to reach streams. A forest stores about 10 times more water than a typical suburban development. As a result of
our forested South Hills, a heavy rainfall will be largely absorbed. Stream flows will increase
only modestly, even after an inch of rain has fallen on the area. Without this natural stormwater
control, upper Amazon Creek would look more like a river after a heavy rainfall. The property owner’s current plan envisions 110 houses on the is site. This would result in
about 20 acres of impervious surface area, according to city estimates. The entire site has steep
slopes in excess of 10 percent. The benefits from maintaining this land in its natural state could be quantified in terms of the
monetary savings resulting from not building and maintaining downstream stormwater
management facilities and programs that would otherwise be needed. Water Quality Benefits As with stormwater management, the EAH land provides a unique benefit in maintaining local
water quality. The natural forest reduces soil erosion by reducing the volume and speed of
runoff from heavy rains. Soils are stabilized by natural vegetation. Sediments are filtered by
plants and organic matter on the forest floor. Natural wetlands on this site serve to further
enhance water quality. Overstory trees provide shading, keeping water temperatures low. Development of this site will disrupt the natural hydrology of the area, impacting wetlands,
accelerating runoff, increasing soil erosion, and degrading water quality. Stream bed will be
deepened and channelized by the increased runoff. Downstream impacts include turbidity and
sedimentation that cause harm to salmon-bearing streams. Accelerated runoff due to tree removal, soil compaction, and impervious surfaces from roads,
homes and driveways, will reduce the amount of water stored in the ground. Without fully
charged groundwater, streams will dry out more quickly in the summer, harming the fish and
wildlife that depend on them. Residential Land Supply Preservation of this site will have almost no impact on the residential land supply within the
Urban Growth Boundary. An appraisal on this property done for the city by Duncan and
Brown, Inc. on October of 2004, shows that the practical development of this site is with only
seven homesites. This is based on an assessment by Poage Engineering that this is the highest
and best use of this property, given the physical constraints of the site. •
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