Flooding FAQs

What kind of weather should I worry about? 

If Nampa had a torrential rainstorm, for instance, one that approaches 1 inch of rain in an hour, or ongoing heavy rain for several hours there could be problems. If weather were to drastically warm up and melt the snow in less than say 4 hours there could be some concerns because of the total volume of water. However, current forecasts do not indicate these kind of weather patterns. 

What is localized flooding? 

Some call it puddling or ponding. Drainage may be slow in some areas, causing the ponding or pooling of water in rain storms or rapid melting.

There is water standing in the street. What should I do? 

Curbs, gutters and streets are part of the overall storm drainage system in Nampa. However, should water reach the top of the curb or higher we would like to know.  We also want to know if water is completely covering a street or roadway. Likely it is a local problem such as a plugged catch basin, usually blocked by debris or ice, but we still like to check it out.  Drivers should always use caution and slow down if you drive through standing water.The Nampa Street Division has staff on call 24 hours a day to address citizen’s concerns.

When should I call for help?

If water reaches the top of the curb or goes over the curb, please call or email the Street Department.  
You can call the Street Division at 468-5831 or email [email protected]. 
If you have an after-hours emergency, please call Nampa Dispatch’s non-emergency number at 465-2257. 

How does the City prepare for flooding? 

The city of Nampa pays close attention to flood risks. Our team consists of trained staff that monitor National Oceanic and Atmospheric Administration (NOAA) data and snow water content. Preventative crews are called in and dispatched, when necessary, to assure that critical storm drain lines and catch basins are open. 

What is all this talk about storm drains? 

Streets are graded (sloped) to direct rain/water to catch basins. The catch basin is the inlet to a storm drain pipe. You can check this map (https://nampa.maps.arcgis.com/apps/webappviewer/index.html?id=08d6d3987e3c4bc296cfa586b617dba4) to see if you have catch basins near your home. 

Where does all this water go?

Stormwater in Nampa goes several places and the city manages stormwater in accordance with the federal Clean Water Act.

• Ponds – Some areas drain to ponds that may or may not drain into the ground quickly.  Don’t be surprised if you see standing water in a pond after a storm or snow melt.
• Ground – Some areas drain into the ground through facilities called infiltration beds.  Infiltration beds are often underground packages of rock that provides drainage as the water enters the soil.
• Drains and streams – Some areas drain to streams such as Indian Creek or Mason Creek or drains such as Wilson Drain or Elijah Drain.

How can I help? 

Make sure your storm drain/catch basin is free of ice and debris so melting snow and/or rain have a place to go.