Willdan (WLDN) 8-K/A Independent Accountants Review’ Report

Exhibit 23.1

CONSENT OF INDEPENDENT ACCOUNTS

We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (Nos. 333-139127, 333-152951, 333-168787 and 333-184823) of Willdan Group, Inc. of our reports dated May 3, 2013, May 9, 2014, November 26, 2014 and January 5, 2015 relating to the consolidated financial statements of 360 Energy Engineers, LLC.

/s/ Christopher Kohart

Christopher Kohart, Certified Public Accountant

Lawrence, Kansas

March 26, 2015

901 Kentucky · Suite 301 · Lawrence, Kansas 66044 · Phone: 785.856.2882 · Fax: 785.856.2284 · www.kohartaccounting.com