Powerline Plan and Environ. Assessment Jan. 2013 - Flood Control ...
Powerline Plan and Environ. Assessment Jan. 2013 - Flood Control ...
Powerline Plan and Environ. Assessment Jan. 2013 - Flood Control ...
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<strong>Powerline</strong> <strong>Flood</strong> Retarding Structure<br />
Pinal County, AZ<br />
Draft Supplemental Watershed <strong>Plan</strong><br />
<strong>and</strong> <strong>Environ</strong>mental <strong>Assessment</strong><br />
3. ECONOMICS<br />
This section provides an abbreviated summary of the economic evaluation conducted in support<br />
of the Supplemental Watershed <strong>Plan</strong> <strong>and</strong> <strong>Environ</strong>mental <strong>Assessment</strong> for the PVR project. The<br />
reader is referred to the full economic evaluation technical memor<strong>and</strong>um for further details <strong>and</strong><br />
information.<br />
The PVR economic evaluation is documented in the following report:<br />
• <strong>Powerline</strong>, Vineyard Road <strong>and</strong> Rittenhouse <strong>Flood</strong> Retarding Structures Supplemental<br />
Watershed <strong>Plan</strong>/<strong>Environ</strong>mental <strong>Assessment</strong> Economics Evaluation Technical<br />
Memor<strong>and</strong>um. (Gannett Fleming Inc. <strong>Jan</strong>uary, <strong>2013</strong>)<br />
3.1. Economics Evaluation Technical Memor<strong>and</strong>um Summary<br />
The economics evaluation was prepared in support of the <strong>Powerline</strong>, Vineyard Road <strong>and</strong><br />
Rittenhouse <strong>Flood</strong> Retarding Structure Supplemental Watershed <strong>Plan</strong> <strong>and</strong> <strong>Environ</strong>mental<br />
<strong>Assessment</strong>s (<strong>Plan</strong>/EAs). The memor<strong>and</strong>um describes the methodology <strong>and</strong> summarizes the<br />
results of the benefit-cost analysis. The analysis was conducted on the following two<br />
alternatives:<br />
• Alternative 8A: Replace <strong>Powerline</strong> FRS, Rehabilitate Vineyard Road FRS, <strong>and</strong> convert<br />
Rittenhouse FRS to a levee,<br />
• No Federal Action Alternative (Future Without Project)<br />
The benefit-cost analysis follows the procedures outlined in the Economic <strong>and</strong> <strong>Environ</strong>mental<br />
Principles <strong>and</strong> Guidelines for Water <strong>and</strong> Related L<strong>and</strong> Resources Implementation Studies<br />
(P&G), the Natural Resource Economics H<strong>and</strong>book Part 611 – Water Resources <strong>and</strong> the<br />
National Watershed Manual (Dec 2009). All values in the analysis are in 2012 prices <strong>and</strong> all<br />
annual values have been discounted using the FY2012 federal discount rate for water resources<br />
projects of 3.750 percent. Economic values were derived based on each of the three dams as a<br />
single analysis unit.<br />
The study area for the economics evaluation encompasses approximately 54.5 square miles<br />
immediately downstream of the <strong>Powerline</strong>, Vineyard <strong>and</strong> Rittenhouse dams in Maricopa <strong>and</strong><br />
Pinal Counties, AZ. The study area for the project was defined as the limits of the 100-year<br />
floodplain downstream of the three dams without the dams in place. This area encompassed the<br />
farthest extent of flooding for the combination of alternatives <strong>and</strong> storm events examined within<br />
the scope of the project. Study area l<strong>and</strong> uses include agriculture, residential, commercial,<br />
industrial, institutional, <strong>and</strong> infrastructure.<br />
3.1.1. Study Area Inventory<br />
To identify study area l<strong>and</strong> uses, GIS tax parcel data was obtained from the Maricopa <strong>and</strong> Pinal<br />
Counties Tax Assessor’s Offices. A database of tax parcels within the study area limits was<br />
created using ArcGIS. The parcels were then divided using the Assessor’s Use Code<br />
descriptions into the following categories:<br />
• Residential – existing residential properties<br />
• Residential(new) – residential properties under construction, or imminently to be<br />
constructed<br />
USDA- NRCS <strong>Jan</strong>uary <strong>2013</strong><br />
Kimley-Horn <strong>and</strong> Associates, Inc. Page 9