Mention your name and a short description of who you are. Download and complete the appropriate King County construction dewatering application from the KCIW Construction dewatering webpage.Instructions for completing the Third Party Letter of Authorization (LOA). Need help downloading or filling forms? The Assured and Adequate Water Supply Rules, A.A.C. R12-15-701 et seq. Completed Application: Sixteen copies. Use black ink or type to fill out completely and legibly. A KCIW staff member or your renewal letter may instruct you to fill out a survey. The signatures and notary stamp should be clear, and all signatures must be originals. Please fill the fields out below for yourself.