Does artificial turf count as impervious surface on your stormwater bill or lot coverage?

Two questions, two offices

When someone asks whether turf counts as impervious, they usually mean one of two things.

• The stormwater bill. Many cities and counties charge a yearly stormwater fee, and some size it by how much of the lot sheds water. If turf counts, a bigger turf yard can mean a bigger bill.
• The coverage limit. Zoning codes cap how much of a lot can be impervious. If turf counts, it uses up room you may want for a patio or pool deck, or it can stop the layout outright.

One office rarely answers both, and an HOA can set limits of its own on top of either.

What the codes share is how they define the word. They judge a surface by what it does to water soaking into the ground, not by what it’s made of. Denver counts surfaces where “the infiltration of stormwater into the earth has been reduced by the works of man.” Jacksonville counts a surface “compacted or covered with a layer of material so that it is resistant to infiltration by water.” So a product’s drainage rating doesn’t settle it alone. The office is asking about the whole build, base and soil included. Our article on how rain moves through a turf base covers that part.

Denver: billed by the square foot

Denver’s storm drainage charge is built from impervious area. The city works out what share of the lot is impervious, puts the lot in a ratio group, and multiplies that group’s rate by each 100 square feet of impervious surface (DRMC Sec. 56-112). Higher ratio groups carry higher rates (Sec. 56-113). If turf were counted, it would add square footage and could also move the lot into a higher group.

The code never mentions turf. It defines pervious surface as land that absorbs stormwater at or above the rate it did in its natural, undeveloped state (Sec. 56-109). The city may measure on site, use assessor records, or estimate from aerial photography.

If your bill changes after an install and you disagree, ask the part of Denver’s Department of Transportation and Infrastructure that assessed the charge for a revision. The request has to be in writing, within one year of the bill (Sec. 56-114). Commercial sites face a separate question about required landscaping, covered in Denver’s zoning code and turf. More on the city is on our Denver page.

Jacksonville: three tiers for a house

Jacksonville bills a detached single-family home in one of three tiers by impervious area: 1,549 square feet or less, 1,550 to 4,650, or more than 4,650. Nonresidential property pays per 3,100 square feet of impervious area (Ordinance Code Sec. 754.106).

Turf isn’t named. The definition counts surfaces compacted or covered so they resist infiltration, and includes semi-pervious surfaces such as compacted clay and gravel used as travelways (Sec. 754.102). For most houses it comes down to arithmetic: how far is the impervious area on record from the next tier line, and would the turf cross it if counted?

If you think a charge is wrong, Sec. 754.108 says to petition in writing under the city’s Adjustment and Credit Manual. This fee covers Jacksonville itself, not Jacksonville Beach, Atlantic Beach, Neptune Beach or Baldwin.

The zoning code is clearer on one point. Its definition of landscaping covers grass, ground covers, shrubs, trees, rocks, mulch and more, “but not paving, synthetic plant material or synthetic lawns” (Sec. 656.1601). So turf won’t count toward landscaping a site is required to have. The same section measures lot coverage by buildings. See our Jacksonville page for more on the city.

Horry County and Myrtle Beach: flat for a house

In unincorporated Horry County, a detached single-family home is billed for one equivalent residential unit unless it sits on more than 12 acres (Code Sec. 17.7-17). Turf doesn’t change that charge. Other property is billed by its impervious percentage, in bands from less than 1 percent up to 90 percent and above.

For that property the definition matters, and it leans against turf without naming it. Sec. 17.7-16 lists as impervious “compacted gravel and soil surfaces, awnings and other fabric or plastic coverings.” An appeal goes in writing to the county engineer within 30 days of the bill, with a survey by a registered land surveyor or professional engineer showing the impervious area (Sec. 17.7-20).

The City of Myrtle Beach also bills an individually metered single-family home one unit (Code Sec. 18-62). Commercial sites, condominiums and apartment buildings of three or more units are billed on a standard factor of 80 percent of the site’s total area. Schools and churches have their actual impervious area measured. Only nonresidential sites can ask the city to adjust the impervious area it used (Sec. 18-64).

Coverage is the live question in Myrtle Beach. The zoning ordinance counts as impervious any material that “prevents, impedes, or slows infiltration” compared with soil that carries plants, and as pervious any material that permits “full or partial absorption” (Appendix A, Sec. 203). Turf is in neither definition, and either could be read to fit it. Ask the city’s zoning staff before you plan close to the limit. Our Myrtle Beach page covers more about the city.

North Myrtle Beach has a written test instead. On single-family and duplex lots, a surface counts as pervious only if it takes in water at 2 inches an hour or more, is installed to the manufacturer’s specification, passes inspection and is maintained. Otherwise it’s impervious “regardless of material type or labeling” (Sec. 23-129.4). Lots on the North Carolina side work differently, and our guide to built-upon area in the Carolinas covers them.

St. Johns County: the coverage cap

St. Johns County caps impervious surface at 70 percent of the lot in its RS and RG residential districts, apart from a cap of 20 to 35 percent on buildings (Land Development Code, Table 6.01). Its definition of impervious surfaces is a short list: buildings, concrete, pools, wet retention or detention areas, pavement, and compacted materials used for parking or roads (Article XII).

Turf isn’t on that list. That reads in your favor, but it’s a reading, not a ruling, so get the county’s answer in writing. We didn’t find a county stormwater fee for unincorporated land. If your tax bill shows one, ask the office it names.

St. Augustine Beach: a fee and a tighter cap

The City of St. Augustine Beach, inside the county, has both. Its stormwater fee bills a single-family lot by impervious area in three tiers: 400 to 2,500 square feet, 2,501 to 5,200, and 5,201 or more. Lots with less than 400 aren’t assessed (Code Sec. 7-7). Lawns, gardens and unpaved areas are listed as pervious, and maintained permeable pavers and other alternative porous pavements aren’t counted as impervious (Sec. 7-1).

The zoning cap is lower than the county’s: 40 percent impervious in low density residential and 50 percent in the medium districts (Sec. 6.01.02). One trap: the city’s list of alternative porous paving includes “porous turf,” among techniques for driveways, patios and parking. The code doesn’t say that means artificial grass, so don’t plan a layout around it. More is on our St. Augustine Beach page.

Florida’s turf rule doesn’t answer it

Florida’s turf standard, in force since May 19, 2026, requires turf on single-family lots of an acre or less to be “permeable and affixed to permeable backing with a pervious subgrade” (Rule 62-308.100). It doesn’t say how a city must count that turf for coverage or a fee.

Florida DEP says local governments can still regulate turf as long as they stay consistent with the standard, and that the rule doesn’t address HOA requirements or deed restrictions. What an HOA can decide is in can my HOA stop artificial turf. If low ground on the lot is a swale or retention area, see turf in a swale or retention area first.

Before you build

1. Find the right office. City limits decide whether the city or the county bills and zones your lot.
2. Ask how a house is billed at your address: flat, by tier, or by the square foot.
3. Get your current numbers: the impervious area on record and your coverage limit.
4. Ask how turf and its base will count for the fee and for coverage, and what drainage data or drawings they want to see.
5. Get the answer in writing, with the code section, and keep it with the layout.

On the free visit we measure the space and check the ground, so you’ll have the square footage to give that office. Our guide to whether turf counts as impervious has more questions to bring.