If you live near Lake Minnetonka, the size of your next patio may be decided before anyone draws it. Lake-area cities cap how much of a lot can be covered by hard surfaces, and that cap is called a hardcover or impervious-surface limit. This guide explains what counts, where the limits come from, where the Minnehaha Creek Watershed District fits in, and what permeable pavers can and can't do. Your city has the final word on all of it, so check with the city before you plan around a number.
What hardcover is
Hardcover and impervious surface mean the same thing: constructed surfaces that keep rain from soaking into the ground, so it runs off instead. Roofs, driveways, patios, walks and pools are the usual examples. The limit is a percentage: the area of hard surface on the lot divided by the area of the lot.
What counts is set by each city's definition, and the definitions differ:
- Minnetonka Beach counts rooftops, decks, sidewalks, patios, swimming pools, parking lots, concrete, asphalt, gravel driveways and pathways, and permeable pavers. Retaining walls count unless the city engineer finds a wall is the minimum needed to control erosion, while isolated landscape boulders and the riprap a shoreline needs don't count (Zoning Ordinance Appendix A, Section 2.4).
- Woodland lists roofs, awnings, concrete or bituminous driveways, walkways, tennis courts, swimming pools, patios and plastic landscaping sheets, and counts slatted decking as 90% impervious (City Code Chapter 9, Section 900.02, Subd. 23).
- Shorewood's impervious surface handout, a city handout that summarizes its code, lists decks, gravel driveways, permeable pavers and artificial turf as impervious.
That's why the same patio can count differently from one town to the next.
Where the limits come from
Under state law, land within 1,000 feet of a lake is shoreland (Minnesota Statutes section 103F.205), so a home doesn't need lake frontage to be in it. The DNR's shoreland rules set the standards cities build into their shoreland ordinances, including this one: "Impervious surface coverage of lots must not exceed 25 percent of the lot area" (Minnesota Rules 6120.3300, subpart 11).
Cities adopt their own ordinances and set their own numbers, so the limit on your lot can be 25 percent, higher, or different depending on the size of the lot. Many cities also limit how close to the water any hard surface can go. Here's what three city codes say.
Three examples from city code
Tonka Bay
The whole city is in the shoreland district. The maximum impervious surface coverage is 25 percent of the lot area, and no impervious surface can go within 50 feet of the ordinary high water level except stairways, lifts and landings. A variance application for impervious surface has to include a stormwater treatment plan, reviewed by the city engineer (City Code Section 1070, Sections 1070.05 and 1070.11). More on our work there: Tonka Bay landscaping.
Minnetonka Beach
Hardcover can't exceed 30 percent of a lot (Section 8.2.1 and Table 6.3.3). No hardcover is allowed within 75 feet of Lake Minnetonka's ordinary high water level, except the stairways, lifts and landings Section 6.2.7(B) allows, or within 25 feet of a wetland (Section 6.2.7 D). And as noted above, permeable pavers count as hardcover under the city's definition. More on our work there: Minnetonka Beach landscaping.
Woodland
On lots over 16,500 square feet, impervious surface, buildings included, can't exceed 25 percent of the lot area, the main building alone can't exceed 10 percent, and a lot already over the limit can't be reconfigured without a variance. On smaller lots with city water and sewer, the cap is 40 percent, and it can go to 45 percent with a conditional use permit. Land below the ordinary high water level, wetlands, and road and driveway easements don't count toward lot area (Section 900.10). More on our work there: Woodland landscaping.
Every other city around the lake sets its own limit. Ask the city's planning department for the number, or ask us to check it as part of your project.
Where the MCWD fits
The Minnehaha Creek Watershed District regulates stormwater, erosion and shoreline work across the Lake Minnetonka area, but on a typical house lot the hardcover number is the city's. Under the MCWD's Stormwater Management Rule, effective April 29, 2024, single-family work on an existing lot doesn't need a stormwater permit unless the new and reconstructed impervious surface reaches one acre. Other MCWD rules can still apply, especially to shoreline work like riprap, and we handle MCWD-DNR shoreline permitting in-house.
How permeable pavers work
Permeable pavers look like a regular paver patio, but they're laid with wider joints over an open stone base, so rain soaks down through the patio instead of running off it. That can help with drainage on a lot where water has nowhere else to go. Our paver patio guide covers how a patio base is built.
Do permeable pavers count toward hardcover?
They can, so don't assume they're exempt:
- Minnetonka Beach's code counts permeable pavers as hardcover.
- Shorewood's city handout says permeable pavers count as impervious, and that green roofs, rain gardens and other treatment systems get no credit toward the limit.
- The DNR's guide to impervious surface standards points to a county definition that includes permeable pavers, and explains that the shoreland rules limit hard surface to leave room for vegetation and habitat.
Ask your city whether permeable pavers count on your lot, and get the answer before the patio is designed around it. Where they count, they can still be worth it for drainage. They just won't buy you more patio.
Planning a patio on a lot near its limit
- Find your city's limit and definition. The planning department can tell you the percentage, what counts, and how close to the water hard surfaces can go.
- Get your existing hardcover measured. Cities often want existing and proposed hardcover calculations with the permit application, and some recommend a land survey.
- Size the patio to the room you have. Taking out an old walk or a section of driveway can free up room for a patio, if the city counts both the same way.
- Ask about a variance only after that. Variances exist, but they take time and come with conditions, like Tonka Bay's stormwater treatment plan.
We do this as part of the job. Our design partner draws a scaled 2D plan and a full 3D rendering that size the patio, walks and beds to the lot before anything is built, and we pull the permits. Landscape design runs $500 to $3,000 most of the time, and paver patios start around $6,000.
Hardcover and permeable paver FAQ
What is hardcover?
Hardcover, also called impervious surface, is any constructed surface that keeps rain from soaking into the ground, such as roofs, driveways, patios, walks and pools. Each city defines exactly what counts, and some include decks, gravel driveways and permeable pavers.
What is the hardcover limit around Lake Minnetonka?
It depends on the city. The state's shoreland rules set 25 percent of the lot area as the standard for shoreland lots, and each city sets its own limit in its ordinance. Tonka Bay's code sets 25 percent citywide, Minnetonka Beach's sets 30 percent, and Woodland's sets 25 percent on lots over 16,500 square feet and 40 percent on smaller lots with city water and sewer. Check with your city for your lot.
Do permeable pavers count as hardcover?
They can. Minnetonka Beach's code counts permeable pavers as hardcover, and Shorewood's city handout says they count as impervious. Never assume permeable pavers are exempt. Ask your city before the patio is designed around them.
Does the MCWD set my hardcover limit?
Usually not. On a typical house lot, the hardcover limit comes from the city. Under the MCWD's Stormwater Management Rule, single-family work on an existing lot doesn't need a stormwater permit unless the new and reconstructed impervious surface reaches one acre. Other MCWD rules can still apply to shoreline work, and we handle MCWD-DNR shoreline permitting in-house.
How close to the lake can I put a patio?
Each city sets its own rules. Tonka Bay's code allows no impervious surface within 50 feet of the ordinary high water level except stairways, lifts and landings. Minnetonka Beach's allows no hardcover within 75 feet of Lake Minnetonka's ordinary high water level except the stairways, lifts and landings its code allows. Check your city's shoreland rules before you plan.
Do decks and gravel driveways count?
Often, yes. Minnetonka Beach's definition includes decks and gravel driveways, Shorewood's city handout counts both, and Woodland's code counts slatted decking as 90 percent impervious.
What if my lot is already over its limit?
Talk to the city before you add anything. Cities handle this through a variance, which can come with conditions. Tonka Bay requires a stormwater treatment plan with a hardcover variance application, and Woodland doesn't let a lot over 16,500 square feet that is already over its limit be reconfigured without a variance.
How much does a permeable paver patio cost?
Our paver patios, permeable or standard, start around $6,000 and rise with size, materials and access. Landscape design runs $500 to $3,000 most of the time.
Can you help me figure out what fits on my lot?
Yes. Our design partner draws a scaled 2D plan and a full 3D rendering that size the patio, walks and beds to the lot, and we check your city's hardcover rules and pull the permits as part of the job.