While we appreciate the beauty and recreation of the Boise River as it meanders through Garden City, we can never ignore the potential damage the river could have on all of us. It is never too early to be thinking about how the seasonal events of the River affect our community. On average, the Boise River reaches 7,000 cubic feet per second (CFS), or flood stage at the Glenwood Bridge, once every 5 years. So far, this has resulted in some minor inconveniences and damage; however, future flooding may result in substantial expense to the community.
For more information related to permits needed to do work within the floodplain please refer to the Floodplain Development.
The U.S. Army Corps of Engineers, Walla Walla District (USACE), along with the City of Garden City, Idaho is conducting a General Investigation (GI) Study with the purpose of addressing flood risk in the vicinity of Garden City. This GI study is in response to the frequent flooding in Garden City resulting in threats to property, critical infrastructure, and life-safety. In addition, population growth and development in the floodplain in Garden City has increased risk of damages and severity of flooding. The intent of the Garden City Flood Risk Management GI Study is to analyze potential structural and nonstructural solutions to reduce risk to human life and safety, critical infrastructure, and reduce risk of economic damages from flooding events.
General Investigation studies are authorized and appropriated by Congress to address water resources problems including flood risk management, navigation, ecosystem restoration, and coastal storm risk management. Through these studies, alternative plans are compared, and favorable and unfavorable characteristics are determined. Costs and benefits of alternative plans are identified, and a specific course of action is recommended to Congress. Congress may then authorize and fund a project for construction. There is no designated limit to the scale, extent, or cost of development that can be proposed as the result of a GI study.
We can never ignore the potential damage the river could have on all of us. There are roughly 1,700 properties in the regulatory floodplain, with an estimate of 74% of properties in Garden City in the 100-year floodplain. It is sensible to be aware of how the seasonal events of the river affect our community. On average, the Boise River reaches 7,000 cubic feet per second (cfs), or flood stage at the Glenwood Bridge, once every 5 years. This year it is anticipated that the river will reach beyond 7,000 cfs.
For more information click on the "Prepare for Flooding" link above.
For purposes of the Garden City Code, the riparian area is considered the area between the ordinary high water mark of the Boise River including tributaries where water comes from and flows back into the Boise River and the greenbelt and/or nature path; or where there is no greenbelt and/or nature path adjacent to the river or tributary, the area measured twenty-five feet (25') in width from the riverbank. Before doing work or landscaping in the Riparian area find out the regulations and permits necessary. LINK
Find out what flood services Garden City provides by clicking the link above
Resources
Flooding Emergency - CALL 911
If you wish to be notified by your local emergency response team in the event of emergency situations or critical community alerts please sign up for Code Red. Examples include: evacuation notices, bio-terrorism alerts, boil water notices, and missing child reports. Code Red link.
Digital Flood Insurance Rate Map (DFIRM) DFIRM link Adopted 2003 maps
Boise River Flood Inundation Maps: These two interactive maps depict fifteen different flow rates of the Boise River from just below Lucky Peak Dam to the Ada/Canyon County border. The flow model used provides the best analysis of flooding and flood depths that it can.
Boise River Enhancement Network (BREN) BREN works to ecologically enhance the Boise River, and is a great resource for information, events, and activities
Silver Jackets Silver Jackets teams in states across the United States bring together multiple state, federal, and sometimes tribal and local agencies to learn from one another in reducing flood risk and other natural disasters. http://www.nfrmp.us/state/
A new FEMA webpage is now available as a one-stop-shop to the public about how to protect themselves and their property from the nation’s number one disaster, flooding. The webpage includes free resources and information to learn about, understand, and take action to reduce flood risk.
The FEMA Map Service Center allows visitors to enter a street address to learn more about flood risks their community. Other information includes resources about flood maps, flood zones, flood risk and flood insurance.
In addition to learning about flood hazards, visitors may also explore the National Risk Index. The tool identifies communities nationwide most at risk to 18 natural hazards and shows how certain factors such as social vulnerability, expected annual losses and community resilience affect those risks.
Also, the Flood Risk and Endangered Species Habitat mapping tool provides the species range and Special Flood Hazard Area data needed to integrate wildlife conservation activities into your community's floodplain management program.
There are also multiple resources about how actions the public can take now to protect their property from hazards.
Learn more about other free resources online to become resilient from natural hazards at fema.gov.
Suzanne Sarpong, P.E., CFM Floodplain Management Specialist FEMA Region X Floodplain Management and Insurance Branch 130 228th Street SW Bothell, Washington 98021-9792 Phone: (425) 487-2023 Cell: (202) 655-8765
The FIRMs that were adopted in June 2020 show Garden City in ‘seclusion’. This means that FEMA has secluded Garden City from the changes to the floodplain identified in the model that is the basis for the map changes. This was done to provide additional time for Garden City to explore the feasibility of certifying existing levees or to identify other mitigating measures that the City can take to reduce the footprint of the anticipated floodplain. Therefore, for the time being, there will be no change to the regulatory maps that are currently in effect that determine how flood regulations are applied during construction and are utilized for flood insurance requirements. However, the City advises that you review the maps to see how the anticipated maps might affect your property and flood insurance. Garden City also advises you to speak to your insurance provider about potential changes to insurance rates.