Concrete in Garden City, on the Boise River's floodplain
Garden City wraps around the Boise River. When concrete work involves grading or fill in the floodplain, the city wants a Floodplain Development Application first.
Garden City is a small city of about 14,000 surrounded by Boise, stretched along the Boise River and the Greenbelt. Much of it is in the river's floodplain, and the city regulates that closely. Its Floodplain Development Application is required for grading or placing fill in the floodplain and for any work in the floodway or the river channel, and development beside the river and the Greenbelt has extra rules in the city's code. A patio or driveway that raises the grade, or the fill under it, can trigger that review, so we check the flood map and the city's requirements before we quote.
The river is the reason. In spring 2017, the Boise River peaked at 9,590 cubic feet per second, well above its 7,000 cfs flood stage. Ada County says the river has reached or exceeded flood stage ten times since 1982, and the 1983 peak was 9,840 cfs. Concrete near the river needs a base that drains and doesn't wash out, and a grade that sends water away from the house without pushing it onto the neighbors. Garden City is in Ada County, so ACHD permits work on local streets. Chinden Boulevard, which runs through the city, is a state highway under the Idaho Transportation Department. Our work here ranges from older driveways and walks to patios on river lots and new concrete for infill homes.
What we do in Garden City
Floodplain review
Grading and fill checked against Garden City's floodplain rules; the application filed when needed.
Drained bases
Compacted, drained gravel under slabs on river-bottom soils.
Careful grading
Water directed away from the house and off neighbors' lots.
Infill and older homes
Driveways, walks and stoops for older houses and new infill lots.
ACHD and ITD permits
ACHD for local streets; the Idaho Transportation Department on Chinden.
Repair and leveling
Settled panels lifted where the slab is sound.
Neighborhoods and roads we cover
- Chinden Boulevard corridor
- Glenwood Street
- Adams Street
- Boise River Greenbelt
- Riverside Village
- Plantation area
- Expo Idaho area
- Veterans Memorial Parkway
- 50th Street area
- 36th Street (Boise line)
- Garden City river lots
- Glenwood–Eagle line
Concrete services in Garden City
- Driveways, builder driveway replacement, approaches and sidewalks, RV and parking pads
- Patios, stamped and decorative concrete, walkways and steps, sport courts
- Shed and shop slabs, foundations and footings
- Repair and leveling, removal
Questions from Garden City homeowners
Do I need floodplain approval for a patio?
If the patio involves grading or placing fill in the mapped floodplain, Garden City requires a Floodplain Development Application. A slab poured at existing grade with no fill may not. We check before we quote.
How high did the river get in 2017?
It peaked at 9,590 cfs that spring, against a flood stage of 7,000 cfs. Ada County counts ten times at or above flood stage since 1982.
Who permits the approach on Chinden?
Chinden Boulevard is a state highway, so the Idaho Transportation Department. Garden City's local streets are ACHD's.
Can concrete near the river last?
Yes, with a drained base, reinforcement and the right grade. What fails near rivers is usually the base washing out, not the concrete.
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