Floodplain Functions

Floodplains in our City serve a beneficial purpose to our quality of life. These low areas are where rainfall goes to drain, andDiagram of water on roadway and swales - Cross Section of Typical Roadway when the rainfall drains into the ground, this helps reduce flooding, and recharges our drinking water supply. These floodplains also serve as filters of stormwater runoff as it seeps through the ground and into our aquifer. This aquifer is our only source of drinking water, and this filtering helps contain pollution before it reaches our aquifer! It is important that we appreciate our floodplains, and try to maintain, preserve and restore these areas whenever possible.


A swale is a long narrow depression of land in front of your home adjacent to the street, which varies in depth and is typically wider than it is deep. Swales provide an area for stormwater runoff from roads and other impervious areas to accumulate or pond. Normal time for ponding in swales is typically 24 to 48 hours. Water in swales will eventually evaporate or infiltrate into the soil. Swales filter the stormwater and allow percolation of the water into the soil below.


Swales should have grass, a form of cover that allows percolation into the soil below. Rock or pebbles are not allowed due to compaction of the material, and it does not allow the rainwater to percolate back into the ground. This condition floods your driveway and your neighbor.

Benefits of Swales

  • Improve the look of the neighborhood
  • Provide filtering of runoff Reduce pollutants entering water bodies (canals, rivers, lakes, etc.)
  • Reduce flooding, allow water to pond and protect properties

Maintenance of Swales

  • Clear the swales of any debris including leaves, branches and other vegetation. Allow water to pond.
  • Do not park in swale which causes compaction of the soil and reduces infiltration.
  • Do not pave swales which will reduce the filtration and infiltration of the runoff.
  • Minimize use of fertilizers, pesticides and herbicides.
  • Mow swales, but allow good grass growth.

Map Determinations / Elevation Certificates

The City provides Flood Insurance Rate Map (FIRM) determinations to let you know if you are in a flood hazard area and if you are required to carry flood insurance. If you would like a determination, contact the Building Department at 305-895-9820. You can also refer to the flood zone map on page 17 to determine if your property lies in a flood hazard area.

Flood Elevation Certificates

If you have determined that your house lies in a flood zone, a Flood Elevation Certificate can then tell you how high your house was built in relation to that flood zone. These certificates are required for all new construction and substantial improvements to a structure. A Flood Elevation Certificate is an important document that every homeowner should have, and in case of a disaster, would demonstrate to authorities that your house is at or above the required elevation.

If the certificate shows that your house is lower, then the "50% rule" would apply to your house. What this rule simply means is, if your house is located in a flood zone and is damaged and/or improved to an amount greater than 50% of its market value, it will have to be raised to meet the current elevation requirement.


The city of North Miami collects the Federal Emergency Management Agency (FEMA) Elevation Certificate from home builders/developers as a requirement of their building permit.

Elevation certificates are also required for substantially damaged structures. For more information, call the Building Department at 305-895-9820, Monday through Friday, 7:30 am to 3 pm.

To Obtain Your Flood Elevation Certificate

If your home was built after 1995, you may be able to find your elevation certificate by visiting the North Miami Building Department. If your home was built after 1995, and you are unable to access the information, we may have the information on file but have not scanned the Certificate as of yet. For more information, call the Building Department at 305-895-9820.

Management Plan