HomeMy WebLinkAbout2007-10-03 Agenda Packet - Board (18) Agenda ItemTRUCKEE # �
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Board Information Request
To: Board of Directors
From: Ed Taylor
Date: September 28, 2007
Subject: Soils Map for Prosser Area
1. WHY THIS MATTER IS BEFORE THE BOARD:
This is an informational item to the Board on the Soils Map for the Prosser Area.
2. HISTORY
Several shallow wells in the Prosser Dam Road Area have gone dry this year.
3. NEW INFORMATION
At the September 19, 2007 Board meeting there was a.request by a Board Member for a soils
map of the Prosser area. Staff researched the studies and identified a geological soils map that
was prepare by Hydro-Search Inc. for the District in 1980 and updated in 1995.
Staff digitally copied the soils map over a resent aerial photograph. Please keep in mind that
the accuracy of the map and the photographic overlay are not exact. There can be a wide
variation in the endpoint of the soils locations. Staff also reviewed other sources of information
for soils in the area. All of the information was consistent with the Hydro-Search Inc. map.
The following text comes from the USDA soils data web site:
"The locational accuracy of soil delineations on the ground varies with the transition between map units.
For example, on long gently sloping landscapes, the transition occurs gradually over many feet. Where
landscapes change abruptly from steep to level, the transition will be very narrow."
One of the important items on this map is the extended area of the (Qla) Alder Hill olivine basalt
(lava rock) above Prosser dam Rd. that extends uphill past Tahoe Donner. This material has a
limited ability to convey water, which limits water recharge down hill.
5. RECOMMENDATION:
Informational Only, No action required.
6. ATTACHMENTS:
Aerial photograph/Soils Map
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TRUCKEE DONNER Figure 1
Public Utility District Bike/Pedestrian Trail Route
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