Yes, you can amend 2010, 2011 and 2012. You'll need to finish 2010's amendment and have it submitted by 4/15/2014.
Evan A. Nielsen is licensed to practice law in California and handles federal tax matters throughout the U.S. The information provided here is for educational purposes only and is not intended as legal advice for a particular matter. This response does not create any attorney-client relationship with the author. For specific advice about your particular situation, please consult an attorney.
You should be able to claim the deduction as a Schedule A miscellaneous deduction subject to the 2% of a.g.i. limitation.
This is not legal advice nor intended to create an attorney-client relationship. The information provided here is informational in nature only. I may not be licensed in the jurisdiction which you have a question about so the answer could be only general in nature. Visit my website: www.waterstaxlaw.com