Exhibit 31.1

**Certifications**

 

I,Stephen G. Snyder, certify that:

 
| 1.     | I  have reviewed this annual report on Form 40-F of TransAlta Corporation;                                                                                                                                                                                                                                                                |
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| 2.     | Based  on my knowledge, this report does not contain any untrue statement of a  material fact or omit to state a material fact necessary to make the  statements made, in light of the circumstances under which such statements  were made, not misleading with respect to the period covered by this report;                            |
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| 3.     | Based  on my knowledge, the financial statements, and other financial information  included in this report, fairly present in all material respects the  financial condition, results of operations and cash flows of the issuer as  of, and for, the periods presented in this report;                                                   |
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| 4.     | The  issuer’s other certifying officer(s) and I are responsible for establishing  and maintaining disclosure controls and procedures (as defined in Exchange  Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial  reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the  issuer and have: |

 
| a)     |   | Designed  such disclosure controls and procedures, or caused such disclosure controls  and procedures to be designed under our supervision, to ensure that material  information relating to the issuer, including its consolidated subsidiaries,  is made known to us by others within those entities, particularly during the  period in which this report is being prepared; |
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| b)     |   | Designed  such internal control over financial reporting, or caused such internal  control over financial reporting to be designed under our supervision, to  provide reasonable assurance regarding the reliability of financial reporting  and the preparation of financial statements for external purposes in  accordance with generally accepted accounting principles;    |
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| c)     |   | Evaluated  the effectiveness of the issuer’s disclosure controls and procedures and  presented in this report our conclusions about the effectiveness of the  disclosure controls and procedures, as of the end of the period covered by  this report based on such evaluation; and                                                                                        |
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| d)     |   | Disclosed  in this report any change in the issuer’s internal control over financial  reporting that occurred during the period covered by the annual report that  has materially affected, or is reasonably likely to materially affect, the  issuer’s internal control over financial reporting; and                                                                |

 
| 5. | The  issuer’s other certifying officer(s) and I have disclosed, based on our most  recent evaluation of internal control over financial reporting, to the  issuer’s auditors and the audit committee of the issuer’s board of directors  (or persons performing the equivalent functions): |
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| a.     |   | All  significant deficiencies and material weaknesses in the design or operation  of internal control over financial reporting which are reasonably likely to  adversely affect the issuer’s ability to record, process, summarize and  report financial information; and |
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| b.     |   | Any  fraud, whether or not material, that involves management or other employees  who have a significant role in the issuer’s internal control over financial  reporting.                                                                                                 |

 

Dated: March 15, 2007.

 
|   | /s/  Stephen G. Snyder                |   |
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|   | Stephen G. Snyder                     |
|   | President and Chief Executive Officer |

 

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