Pervious vs. impervious, in plain terms
Impervious surfaces keep rain from soaking into the ground: roofs, concrete, asphalt, pavers set on a concrete base, and pool decks. Many cities count the pool too. Pervious surfaces let water through, like grass, planting beds and, in some cities, approved permeable pavers.
South Florida cities limit impervious area to control flooding. Every square foot of new driveway, patio or roof counts against your lot’s limit, so the first question on any project in Southwest Ranches is how much allowance you have left.
The 40% and 60% pervious minimums
In the Town’s agricultural and rural districts, at least 40% of the plot must stay pervious on plots under 2 net acres, and at least 60% on plots of 2 net acres or more. The calculation uses the whole plot minus any street right-of-way (Southwest Ranches district regulations).
Pervious area can count toward landscaping, setbacks, buffers and drainfields, as long as nothing covers it that blocks water from soaking in. The Town Administrator can allow some variation when you add extra drainage or landscaping, but the minimum pervious area can’t drop by more than 10% of the plot area (Southwest Ranches Sec. 080-160).
Driveway setbacks in Southwest Ranches
- Driveways need a 10 by 10 ft sight-visibility triangle on both sides where they meet the street.
- Driveway openings must be at least 45 ft from the nearest local-street intersection, or 80 ft from other intersections.
- Sec. 080-190(B) sets the side setback from interior property lines.
Pergolas, gazebos and new structures
- Every accessory building or structure needs a building permit, with landscaping around it (Ord. 2001-10).
- Septic drainfields can count as pervious area, but you can’t pave or build over them. Locate the drainfield before you design.
Artificial turf and pavers
The Town counts as pervious only surfaces that let water soak in. Ask the Town how it will treat your turf system before counting it toward the 40% or 60% minimum. Lots over 1 acre are not covered by the new state turf rule.
Statewide, Florida now requires DEP standards for synthetic turf on single-family lots of 1 acre or less, and local governments can’t prohibit turf that meets them (Florida Statutes §125.572). The DEP rule took effect May 19, 2026 (Davie staff report). Cities can still regulate drainage, so how turf counts on your impervious calculation is still the city’s call.
A quick example
On a 1-acre plot (43,560 sq ft, under 2 net acres), at least 17,424 sq ft must stay pervious, so up to 26,136 sq ft can be impervious. With a 5,000 sq ft house, a 3,000 sq ft pool and deck and a 4,000 sq ft driveway, about 14,000 sq ft of impervious allowance is left for a barn, pergola or larger driveway.
Your numbers will be different. The Southwest Ranches lot simulator runs the same math for your lot.
See how much you can add
Enter your lot size, what’s already built, and the driveway, pergola or structure you want. The simulator checks your impervious percentage, coverage and setbacks against the Southwest Ranches rules above and shows the largest size that still fits.
Open the Southwest Ranches lot simulator →
The simulator gives a planning estimate, not a permit approval. Rules vary by zoning district, subdivision and HOA. This guide reflects published code as of October 2026, and we confirm the current version and your survey before every submittal. Source: Southwest Ranches Code.
We’re a State of Florida Certified General Contractor (CGC1527850). See our Southwest Ranches service area or Southwest Ranches pool and pergola project.
Frequently asked questions
How much of my lot can I pave in Southwest Ranches?
In the rural districts, up to 60% of a plot under 2 net acres, or 40% of a plot of 2 net acres or more, minus anything else that is impervious.
Does my septic drainfield count as pervious?
Yes, drainfields can count toward the pervious minimum, but they can’t be paved or built over.
Do I need a permit for a pergola or shed?
Yes. The Town requires a building permit for every accessory building or structure.