Exhibit 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We hereby consent to the incorporation by reference in this Prospectus Supplement of Avista Corporation First Mortgage Bonds Series Due 2037 comprising part of the Registration Statement (No. 333-139239) of our report dated March 7, 2006 relating to the financial statements of XL Capital Assurance Inc., which appears as Exhibit 99.1 in XL Capital Ltd’s Annual Report on Form 10-K for the year ended December 31, 2005. We also consent to the reference to our Firm under the heading “Experts” in such Prospectus Supplement.
/s/ PricewaterhouseCoopers LLP
PricewaterhouseCoopers LLP
New York, New York
December 12, 2006
