The location of the five-foot depth contour is critical for the delineation and approval of treatment areas on ANC permits. The MDNR has many inland lakes maps available online to the public. If depth contour maps are not available on the MDNR website for your waterbody, the depth contours in the treatment area may be estimated by using a depth measurement device. Consultants or professional chemical applicators may also offer the service of delineating water depth contours. You may also check local fishing, bait, and sporting good/boating retailers and websites for locally generated lake maps.