Prepare for Flooding

To see current flows, see the River Flow Hydrograph link below. To understand what that might mean for your property see the flood maps below. The maps are interactive depicting the anticipated flooding areas and flood depths depending on the flow of the river.


River Flow Hydrograph

Flood Map  Ulmer Lane West

Flood Map – Ulmer Lane East


Garden City participates with neighboring cities in the Ada City-County Emergency Management Plan. Information related to flood and other emergencies, including warning systems and what to do in a disaster, can be found at  Additional resources related to sandbags can be found here sandbag flyer.


While the river is at or above 7,000 cfs, Garden City will keep the Garden City website up to date with pertinent information.



Each jurisdiction in Ada County, including Garden City, has an agency in charge of flood response. However, these agencies will not conduct flood response activities on private property. It is the agency’s job to protect public roads, buildings, and utilities; and ensure public safety by recommending evacuation or other actions when necessary.


Citizens are responsible for flood response on their own property. Ada City-County Emergency Management (ACCEM) is responsible for coordinating overall efforts and supplying public information. Garden City keeps up to date emergency planning information on its website, including emergency response plans and emergency alerts, and sandbagging information.


Protect Yourself

  • Stay informed

o   Check this website

o   Check the Ada City-County Emergency Management website

o   Sign up for Idaho State Alert and Warning System

o   Sign up for Alerts from Code Red

  • Make sure that your family has an emergency plan in place.
  • If flooding does occur:

o   Evacuate the flood hazard area in times of impending flood or when advised to do so by emergency personnel.

o   Do not let your children or pets wade through flood waters. The water will be dirty and may carry septic water or chemicals.

o   Do not drive through a flooded area. Scouring may have occurred where you cannot see it, and your car may become buoyant.

o   Shut off all electric circuits at the fuse panel or disconnect appliances. Shut off the water service and gas valves to your home.

o   Stay away from flood waters, irrigation ditches, culverts, and storm drains.


Protect Your Property

FEMA offers technical bulletins such as a free guide with techniques to retrofit and flood proof your home or business. They also have financial assistance programs for flood protection. There are a number of these resources available on the Garden City website:


There are methods to reduce risk to your property. For example:

  • Elevate your home’s mechanical and electrical equipment
  • Dry or wetproof your home
  • Grade your property away from structures
  • If flooding is imminent:
    • Store your valuables off-site in a self-storage unit or other safe location, up high, or in a waterproof container.


Build Responsibly- Any type of construction or earth work that occurs in the regulatory floodplain requires a floodplain development application through the city. Before you build on, alter, re-grade, dredge or fill on your property, check with the city to determine if a permit is needed. These types of activities can cause harm and flooding to nearby properties if not done correctly. Not only does city code require a permit prior to construction, but state statutes require that a licensed individual do the work.


Insure Your Property: Ask your agent if you have flood insurance. It takes 30 days after purchase for an insurance policy to take effect.


Protect Natural Defenses

Protect and maintain the natural grading, trees and natural vegetation along the Boise River because they are the first defense against flood damages. The tree roots help sustain and stabilize the bank. The natural vegetation helps reduce velocities and scouring. The open space along the floodplain contributes not only to the scenic beauty of the Greenbelt that borders the river, but the floodplain provides protection for wetlands, rookeries, and fish habitat.                                   


The Treasure Valley has an extensive system of public and private drains and ditches used for irrigation and the movement of water. If these are not kept clean and free of debris, localized flooding can occur, and more sediment can build up in the river channel. If you see dumping or debris in ditches or drains in the City, contact Environmental Services at (208) 375-3194 X 116.