If you are planning drainage work in this metro, the first question is not what to build. It is which city you are in, because the permit threshold varies by a factor of twenty-one between two cities twenty miles apart.

The thresholds, side by side

City	Trigger for a grading or land disturbance permit
Lee’s Summit, MO	More than 2,000 square feet of disturbed ground
Olathe, KS	Any grading or land disturbance activity, no acreage floor
Independence, MO	Grading permit per 2006 IBC Appendix J. Exempt under 1 ft deep and 50 cubic yards on a lot, but only if it does not obstruct a drainage course
Kansas City, MO	1.0 acre (43,560 sq ft). Between 300 sq ft and an acre: no permit, but erosion controls still required
Overland Park, KS	Erosion and sediment control compliance on all land disturbance; KDHE permit coverage at one acre; floodplain development permit inside the FEMA 100-year floodplain

A back yard regrade that requires no paperwork at all in Kansas City can require a city land disturbance permit in Lee’s Summit. That is not a subtle difference and contractors who work mostly in one county get it wrong in the other.

The Independence clause people miss

Independence City Code Sec. 20.05.005 exempts excavation or fill less than one foot deep that does not exceed 50 cubic yards on any one lot. Most homeowner drainage work fits inside that.

The exemption has a second condition attached: and does not obstruct a drainage course. If a swale crosses your lot carrying water from uphill, filling it is not exempt no matter how small the volume. That single clause is the difference between a weekend project and a permitted job.

Above 5,000 cubic yards, Sec. 20.05.004 requires a grading plan prepared by a professional engineer.

The design standards diverge too

This is the part almost nobody knows. Both Independence and Overland Park build to APWA Section 5600, the regional storm drainage design criteria published by the Kansas City Metropolitan Chapter of the American Public Works Association. They are not building to the same version of it.

Independence adopts Section 5600 as approved March 21, 1990 (City Code Sec. 20.02.001).
Overland Park adopts Section 5600 as revised February 15, 2006, and its manual states that future revisions are not in force until adopted in writing by the City Engineer.

Sixteen years apart, on the same regional document, in cities forty minutes apart.

That spread is about to widen. In December 2025, the APWA Kansas City Metro chapter approved an updated Section 5600, merging it with the MARC/APWA BMP Manual after a six-year effort begun in 2019. Adoption happens city by city, by written act of each City Engineer. Expect a 1990 / 2006 / 2025 spread across the metro before it narrows.

Two rules aimed directly at homeowners

Kansas City: no sump or downspout into the sanitary sewer. Ordinance No. 150452, adopted in 2015, prohibits it. KC Water runs a free program, Keep Out the Rain, to find and disconnect existing connections. In the combined sewer core this is not bureaucratic: roof and yard water sent into the sewer during a storm competes with sewage in the same pipe.

Overland Park: sump discharge five feet off the property line. OPMC 7.54.250 requires that water from intermittent discharges such as sump pumps not be discharged closer than five feet to any adjoining property line, so that it percolates on your own ground. Constant discharge reaching a sidewalk or street can be abated as a public nuisance. On a narrow lot, that setback drives the entire discharge design, and no Missouri-side city here has an equivalent rule.

And one difference in how it is all paid for

Kansas City funds stormwater through a monthly per-property utility fee: $0.50 per month for each 500 square feet of runoff surface, under City Code Sec. 61-4. Two credits exist and both reward drainage work, a 50 percent ratio credit at a 30:1 property-to-runoff-surface ratio and a detention credit of 10 to 50 percent for a privately maintained detention structure. You have to apply for both.

Johnson County, Kansas funds stormwater through a countywide one-tenth of one percent sales tax authorized in 1988, distributed through the Stormwater Management Advisory Council. There is no per-property fee, so there is no credit to earn.

Same watershed. Opposite funding philosophy.

Drainage Permit Rules by City: Kansas City Metro Compared

The thresholds, side by side

The Independence clause people miss

The design standards diverge too

Two rules aimed directly at homeowners

And one difference in how it is all paid for

Sources