How much slope does a new patio against a Tulsa house need?

The City's criteria manual asks for impervious surfaces within 10 feet of a foundation to slope at least 1.5 percent away from the building, and for the ground to fall 6 inches across the first 10 feet.

Can a new driveway drain onto the neighboring lot?

Not in a way that causes damage. The manual requires a property to accept and convey drainage without damaging adjoining properties, and any extra flow created on the lot to be collected and taken to the street where that is possible.

Does drainage work with a new slab need a City permit?

All development needs a watershed development permit unless the Watershed Development Regulations exempt it, bare-earth work filed with a building permit needs an approved erosion and sediment control plan, and a stormwater drainage permit applies once the discharge leaving the site exceeds what a 15-inch conduit carries.

Why does water stand on my driveway?

Usually shape rather than concrete. The City's own figure is a drive whose high point is at least 6 inches above the adjacent gutter, so a flat or dished slab holds water wherever the fall ran out.

Tulsa Concrete Drainage Rules | Slopes, Runoff & Permits

Field note, published October 4, 2026. Every source below was read that day.

The City publishes the slopes, so you can measure them

Nearly all the grading rules a homeowner needs sit in one document: the City of Tulsa Stormwater Management Criteria Manual of June 2019, prepared by the Engineering Services Department. Its single lot residential requirements are written for new houses, additions, outbuildings, swimming pools and, in its own words, other significant activities that could change the drainage patterns and characteristics of property in a way that could affect neighboring properties. A patio across the back of a house, or a drive rebuilt two feet wider, is exactly that kind of activity. Retrieved October 4, 2026.

Four figures from that section decide whether a slab sends water the wrong way:

Impervious surfaces within 10 feet of the building foundation are sloped at least 1.5 percent away from the building, which is close to three sixteenths of an inch of fall for every foot you move away from the wall.
Lots are graded so surface water leaves the foundation walls, with a minimum fall of 6 inches across the first 10 feet. Where a lot line, a wall or a slope makes that impossible, the nearest adjacent grade still has to sit at least 12 inches above the flow line of the drainage path running around the structure.
Driveways are shaped so the high point of the drive stands at least 6 inches above the adjacent gutter or edge of paving.
Water gathered in an underground collection system is either taken to the street or let out on the downhill part of the lot, no nearer the boundary than a third of the distance between the property line and the building.

A four-foot level, a tape and a string line will tell you what your ground does today. Check the fall along the wall where a patio would sit, and the shape of the existing drive against the gutter, before anyone quotes. Where the fall is already short, say so when you ask for bids: that problem is solved in the grading and the forms, and it is far cheaper there than after the concrete has gone off.

The rule about the lot next door

The manual is unusually plain about shared water. A residential property has to accept and convey drainage without causing damage to adjoining properties. Flow arriving from off the site cannot be blocked, and flow passing through has to be carried so it does not damage anyone downhill. Any extra flow created on the property has to be collected and taken to the street where that is possible, or to another approved conveyance where it is not.

The City's development policy says the same at a larger scale. Work that raises the impervious area above what was there before, or concentrates flow off the site in a way it did not before, and is detrimental to adjacent properties, has to carry mitigating stormwater controls, and no development may push more flow downstream than the system below it can take. For lots inside a new residential or commercial development the manual caps that sharing outright: no more than two lots or half an acre may drain across an adjacent lot unless the water is held in an approved drainage system component within a drainage easement.

In practice this is the difference between a new patio that annoys the household behind you and one nobody notices. Before the forms go in, walk the property line with the contractor during a storm or after a long hose test, and agree out loud where the water will cross it.

How much more water a slab actually makes

The same manual carries the arithmetic the City's engineers use. Table 6-2 gives paved driveways, roofs and parking areas a runoff curve number of 98, against 74 for lawn in good condition on a group C soil and 80 on a group D soil; the number climbs as less rain soaks in. Paving over turf moves that patch to the top of the scale permanently.

Table 6-1 supplies the rain to put against it, from NOAA Atlas 14 for the Tulsa gauge, station 34-8987. A one-hour storm of the kind expected every second year drops 1.64 inches. The one percent storm, the one commonly called the hundred-year event, drops 3.94 inches in an hour and 9.03 inches over 24 hours, and that 24-hour event is the design storm the City uses for hydrology. Run the smaller of those figures across a 600-square-foot patio and roughly 600 gallons has to leave the slab somewhere, by arithmetic on the published depth rather than any local measurement.

Which is why a conversation about a new slab is really a conversation about the twenty feet downhill from it.

The permits that come with the water

Tulsa requires a watershed development permit before developing, redeveloping, building, excavating, grading, regrading, paving, filling, berming or diking any property in the city, and the manual names five kinds: floodway, floodplain, stormwater drainage, stormwater connection and earth change. All development needs one unless the Watershed Development Regulations specifically exempt it, so for a patio or a drive the real question is which of the five applies, and that question belongs to the City rather than to a contractor.

Two thresholds are published and worth carrying into a conversation. A stormwater drainage permit is required once the discharge leaving the site is more than a 15-inch diameter conduit could carry. An earth change permit arrives when the work disturbs an acre or more. Floodway and floodplain permits attach to any development or earth change inside the regulatory floodplain or floodway, which is a live question on lots near a creek.

The City's Development Services infrastructure development page says the division reviews and issues watershed development permits, that applications go through the City's self service portal or the infrastructure development coordinator, and that every building permit and watershed development permit disturbing bare earth has to come with an erosion and sediment control plan at the time of application. The criteria manual is firmer still: each residential building permit and earth change permit must have an erosion control plan approved before it is installed and inspected by the City, and construction, including any fill, cannot begin until that is in place.

On a big job the state joins in. The Oklahoma Department of Environmental Quality construction stormwater page requires coverage under general permit OKR10 for activity disturbing one acre or more, or under an acre when it forms part of a larger common plan of development or sale greater than an acre. Coverage means a notice of intent filed before construction starts and a stormwater pollution prevention plan put into practice; the page lists a $100 application fee plus an annual fee of $347.71, and about 14 days to process a notice. Household flatwork stays well under that acre, while a commercial lot being resurfaced can pass it. Retrieved October 4, 2026. Once a site is under such a plan, the criteria manual expects its controls to be inspected every 14 days and within 24 hours of any rainfall over half an inch.

Where to send the water

Shaping the slab comes first, because concrete sheds everything that lands on it and the cheapest drain is a surface that falls the right way. After that the usual answers are a shallow grassed swale along a boundary, a trench drain across a garage apron where a drive runs downhill at the door, a channel drain at a low spot, a buried line with a visible outfall, or, on a street with a ditch rather than a curb, a culvert under the drive. The manual sizes those culverts to pass the one percent design flow, which is another reason the pipe diameter is not a guess.

For the infiltration route, the Tulsa Planning Office publishes a rain garden guide: keep the garden at least 10 feet from any building, dig it 6 to 8 inches deep, size it at 5 to 10 percent of the hard surface draining into it, and test the ground first, because it has to take in at least half an inch an hour. Its worked example turns a 1,200-square-foot roof into a 60-square-foot garden, and its test is simply timing how long an eight-inch hole takes to empty, as read on October 4, 2026. On tight clay that test often fails, and the honest answer then is to carry the water somewhere rather than ask the ground to drink it. The guide also tells you to have utilities located before digging, and the notice period Oklahoma law sets for that call is in the driveway permit note.

One more question belongs in every quote: where the chute and the barrel are rinsed at the end of the pour. The City's stormwater chapter exists to prohibit illicit discharges into the municipal separate storm sewer system and to control the dumping or disposal of anything other than stormwater into it, so wash water carrying cement has no business going down a street inlet.

Put these in the written scope

The fall away from the house along every foot of a slab that touches it.
The high point of a new drive measured against the gutter or edge of paving.
Where runoff leaves the concrete, and what receives it there.
Any drain, swale or culvert, with its size, its depth and its outfall.
Erosion and sediment control during the work, and who restores the ground afterwards.
Which permit the job needs, if any, and who files it.
Where concrete wash water goes.

The patio guide and the driveway guide cover the rest of what a bidder will ask about those two jobs. For the part of a drive that crosses public right-of-way, the driveway permit note has the City's permit, fee and inspection call, and the curing note deals with the weather on the day the trucks arrive.

Where the water goes after you pour in Tulsa