**Exhibit 12.1**

 

**CERTIFICATIONOF ANNUAL REPORT**

**PURSUANTTO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**

 

I, Harrie L.J. Noy, certify that:

 

1.                                       Ihave reviewed this annual report on Form 20-F of ARCADIS N.V.;

2.                                       Basedon my knowledge, this report does not contain any untrue statement of amaterial fact or omit to state a material fact necessary to make the statementsmade, in light of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

3.                                       Basedon my knowledge, the financial statements, and other financial informationincluded in this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the company as of, and for,the periods presented in this report;

4.                                       Thecompany’s other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange ActRules 13a-15(e) and 15d-15(e)) and internal control over financialreporting (as defined in Exchange Act Rules 13a-15 (f) and 15d-15(f)) for thecompany and have:

(a)                                  Designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that material informationrelating to the company, including its consolidated subsidiaries, is made knownto us by others within those entities, particularly during the period in whichthis report is being prepared;

(b)                                 Designedsuch internal control over financial reporting, or caused such internal controlover financial reporting to be designed under our supervision, to providereasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance withgenerally accepted accounting principles;

(c)                                  Evaluatedthe effectiveness of the company’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

(d)                                 Disclosed in this report any change in the company’s internal control overfinancial reporting that occurred during the period covered by the annualreport that has materially affected, or is reasonably likely to materiallyaffect, the company’s internal control over financial reporting; and

5.                                       Thecompany’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to thecompany’s auditors and the audit committee of the company’s board of directors(or persons performing the equivalent functions):

(a)                                  Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the company’s ability to record, process, summarize and reportfinancial information; and

(b)                                 Anyfraud, whether or not material, that involves management or other employees whohave a significant role in the company’s internal control over financialreporting.
| Date: May 15, 2007  | /s/ Harrie L.J. Noy              |   |
|--------------------------|----------------------------------|--------|
|                     | Harrie L.J. Noy                  |
|                     | Chairman of the  Executive Board |
|                     | (Principal Executive  Officer)   |

 

                                                

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