Call 811 Before You Dig

flag marking underground utility

April is National Safe Digging Month. The Board reminds Iowans to be safe and always call 811 before any digging project. The call is free and Iowa law requires everyone to locate underground utilities before digging. See news release or the Board’s electric and pipeline safety pages.

If an underground utility line is hit while digging, it can cause serious injuries, disrupt service to entire neighborhoods, and potentially result in fines and repair costs. 

To avoid a potential accident caused by excavation, have the location of all underground utility lines marked before excavating by hand or with equipment. To comply with Iowa Code chapter 480, Underground Facilities Information and begin the locating and marking process, a person must contact Iowa One Call at 811 or 1-800-292-8989 a minimum of two days (excluding Saturday, Sunday and legal holidays) before excavation commences.  Iowa One Call is a free service. 

After Iowa One Call is contacted, the following will happen.

  • Operators with underground facilities in the area where the excavation is planned are notified. This includes natural gas and power utilities, communications companies, and cities and towns.
  • Within 48 hours after being contacted, utilities either mark their underground facilities with color-coded paint marks or flags, or notify Iowa One Call it has no lines in the area.

If a contractor is performing the excavation work, a person should make sure that the contractor calls Iowa One Call two days (excluding Saturday, Sunday and legal holidays) prior to the commencement of excavating. 

In the United States, the American Public Works Association (APWA) Uniform Color Codes for temporary marking of underground utilities are listed below:

RED electric power lines, cables, conduit, and lighting cables
ORANGE telecommunication, alarm or signal lines, cables, or conduit
YELLOW natural gas, oil, steam, petroleum, or other gaseous or flammable material
GREEN sewers and drain lines
BLUE drinking water
PURPLE reclaimed water, irrigation, and slurry lines
WHITE proposed excavation limits or route
PINK temporary survey markings, unknown/unidentified facilities

One Call Underground Locate Service, Damage Prevention, One Call Complaints and Violation Enforcement by the Attorney General

Many different kinds of utility services may be buried in the ground on your property. For your safety, Iowa law requires that you always call 800-292-8989 a minimum of two days (excluding SaturdaySunday and legal holidays) in advance to schedule underground utility lines to be located and marked before initiating any digging or excavating project. Visit this web page for more information about damage prevention and Iowa One Call.

The Office of the Attorney General enforces the One Call Law. See more information about One Call Complaints and enforcement through the Attorney General's Office.

Off-site Links

Iowa One CallIowa One Call


CGI (Common Ground Iowa)Common Ground Iowa


Damage Prevention and One Call Contact Information

Cynthia Munyon
Utility Specialist, Safety and Engineering Section
Iowa Utilities Board