One of the timeless appeals to building a new home in the Ann Arbor area is the scenic vistas afforded by the many streams and rivers in Washtenaw and Jackson Counties. The Huron River and its tributaries provide rich landscapes and a lush natural environment that create a kind of oasis from city life. Here, homeowners find a retreat they can come home to every day.

But constructing a new home or building an addition near a body of water in southeast Michigan usually means building on a floodplain. House construction on a floodplain may introduce multiple wrinkles to your home building project — whether it’s a new home or a renovation. The process of building on a floodplain can be complex and confusing, but a knowledgeable design-build partner will walk alongside you to help you realize the home of your dreams.

For many people, the regulations for building on a floodplain are a complete mystery. Let’s explore the basic issues you’ll need to understand, and discuss the options available to you.

Related reading: What to Look for in a Build Site for Your House

What Is a Floodplain?

A floodplain is the land adjacent to a stream or river that experiences occasional or periodic flooding. In the Ann Arbor area, the Huron River is the most prominent water feature with a floodplain, although various other rivers and tributaries in Washtenaw County and Jackson County have floodplains as well. In Ann Arbor, these floodplains include Allen, Malletts, Millers, Swift Run, and Traver Creeks. 

While flooding can occur anywhere, certain areas are especially vulnerable to flooding. These areas are known as special flood hazard areas (SFHA). The Federal Emergency Management Agency (FEMA) has established a base flood elevation (BFE), which is an area with a one-percent chance of annual flooding. If land has been flooded at least once in the past 100 years, it is within the BFE.

Ann Arbor flood maps are available to the public, so that homeowners and home builders can see the locations of highest flood risks. Because flooding in these areas can cause serious and lasting damage to your home, federal and local governments requirements govern any home building project in a floodplain.

To reduce the impact of flooding on homes, FEMA established the National Flood Insurance Program (NFIP)​. NFIP requires homeowners in a floodplain to purchase flood insurance and to follow certain regulations when building a house or renovating a home. If you have a mortgage from a federally regulated lender on a home located in a special flood hazard area, you ​must purchase flood insurance. 

How to Waive the Flood Insurance Requirement

On average, a flood insurance policy in Michigan costs $1,000 per year. However, you can have the coverage requirement waived if you can provide documentation from FEMA that declares your property to be outside of the 100-year floodplain. 

Even if your lot is mapped within the floodplain, it may be worthwhile to have your property surveyed — especially if the land is elevated above other land in the area. If even a portion of your property is above the floodplain, you can apply to waive the flood insurance — as long as your house is built entirely on the elevated area.

If the land survey confirms that it’s within the BFE, you may be able to raise it by adding soil to your property. Depending on how much filling you need, this may be an expensive option, but it’s often worth considering. 

If you choose this option, apply for a Letter of Map Revision Based on Fill from FEMA. There’s a process to follow, and it is critical to do everything in the proper order. Otherwise, FEMA is likely to reject your application. 

Once approved, FEMA will update the community flood map to show that your land is no longer in the high-risk flood zone. Expect the approval to take 6 to 8 weeks for a final determination.

Helpful resource: Everything you need to know about building in a floodplain in Michigan

Building a Home on a Floodplain

If you’re building in the 100-year floodplain, ask your design-build company about the best options for protecting your home from flood damage. There are two main approaches to building in a floodplain:

  • Floodproofing. In floodproofing, the contractor builds up the foundation of your house so that it slopes downward one inch per foot. This is a berm technique that causes water to drain away from the home rather than pooling around the foundation.
  • Structural elevation. This approach safeguards your home from rushing water by building the structure on pilings or stilts. You can also design the home so that water flows entirely beneath the structure.

Each of those approaches affords virtually endless design possibilities. An innovative design-first company will find functional solutions that fit your aesthetic tastes.

What if You’re Remodeling Your Home? 

If you’re building an addition or renovating an existing home that’s on a floodplain, the requirements are somewhat different, depending on your remodeling project.

If the cost of an addition is less than 50 percent of the home’s value, the renovation is not considered a “substantial improvement.” You won’t have to elevate the existing structure or the addition above the BFE. Hire a licensed real estate appraiser to determine if your project will qualify for the exemption.

If the renovation doesn’t meet the 50 percent exemption, you may be able to leave the existing structure as-is, but build the finished floor of the addition above the BFE. In some cases, both the existing structure and the built addition must be elevated above the BFE. 

Enjoy the Home of Your Dreams

Building or renovating a home on a floodplain can be a complicated venture, but that doesn’t mean you have to settle for a disappointing compromise. Your riverside home should be your own personal sanctuary that captures all of the natural beauty of the outdoors — all while providing the functionality you need to enjoy your home on a day-to-day basis. 

Our designers know how to create inspired designs while working within the constraints of building regulations. You can trust Giraffe Design Build to make your house the home of your dreams. 

Get started with us today!