Located right on Lake Winnebago, one of Wisconsin’s largest inland lakes, a home site on Firelane Road in Menasha, Wisconsin, offered its owners the opportunity to build their dream retirement home in an ideal setting. But its proximity to the lake also presented challenges in meeting Department of Natural Resources (DNR) regulations governing waterfront development. Wise selection and creative use of permeable materials resulted in an award-winning driveway design that meets environmental requirements while delivering aesthetic value.
Wisconsin’s water quality standards limit impervious surfaces to no more than 15 percent of any lot or parcel that is within 300 feet of the ordinary high-water mark of any navigable waterway. With the new home set back only 90 feet from the lake and taking up a significant amount of the allotted 15 percent, space for the driveway was limited. There was not enough area left after the home was built to create a standard impervious concrete or asphalt driveway long or wide enough to meet the occupants’ needs, without violating DNR regulations.
Determined to keep their driveway at the size they wanted, the owners set out to find a landscape contractor experienced in working with permeable surfaces. Permeable pavement is allowable in Wisconsin as an alternative to other pavements and stormwater control measures in areas where the adverse impacts of stormwater discharges must be mitigated. A friend of the couple recommended Stumpf Creative Landscapes of Menasha, which had recently completed a few similar projects.
The first step was to determine what sort of permeable surface to use. Permeable driveway options include pervious concrete, porous asphalt and permeable interlocking concrete pavement (permeable pavers). The project owners had initially planned a standard concrete or asphalt driveway, so naturally they at first leaned toward porous asphalt. However, project manager Dan Stumpf Jr. suggested they consider permeable concrete pavers.
While the initial cost of installing pavers was higher than asphalt, pavers offered several long-term advantages. Compared to asphalt, they are exceptionally durable, with a life expectancy of up to 30 years compared to up to 20 years for pervious asphalt. Interlocking pavers are also less costly to repair. Damaged pavers can be removed and replaced when necessary, typically resulting in an invisible repair, while asphalt must be patched — a costly process that can adversely affect the aesthetics of the site. Paver maintenance is also less costly than recoating asphalt. About every five years, the paver joints require a simple blowing out with a power blower, as well as brushing in new chips back over the joint set. In contrast, porous asphalt requires biannual vacuuming and/or washing to retain its ability to incorporate water. Finally, interlocking pavers offer an aesthetic appeal that is difficult to match with any other material.
In the end, the project owners opted for the interlocking permeable concrete pavers. While the initial cost was greater, the long-term maintenance and replacement savings offered value. They also liked the idea of a driveway that was uniquely beautiful as well as practical.
Together, the contractor and homeowners chose County Materials Corporation‘s H20 Pro Pavers for the project. The 3 1/8-inch thick permeable concrete units are promoted as durable and stain-resistant. These units are often used in commercial parking lot applications, making them a good choice for holding up under driveway traffic (as opposed to pavers that are designed primarily for use in patios and walkways).
H20 Pro Pavers are available in three sizes: 4-inch-by-8-inch, 8-inch-by-8-inch and 8-inch-by-16-inch. All three sizes were used for the main part of the driveway. The colors were chosen to coordinate with the colors of the home’s exterior. Several colors were considered, but in the end the couple decided on a custom 75 percent/25 percent mix of Oasis, a blended buff color, and Vision, a solid cream. Combining the two different colors and the three sizes on-site required careful consideration of placement to create a harmonious, uniform effect.
The same paver style in the 4-inch-by-8-inch size was used to create an eye-catching double border. The border consists of a two-layer sailor course in the dark brown Haven color on the inside, edged with a soldier course of the 4-inch-by-8-inch size of the same cream-colored paver used in the drive. The paver colors blend with the home’s siding, brick and trim.
A matching walkway curves gracefully from the drive to the front door, ending in a decorative partial circle to define the entryway. The border’s sailor course was reduced to one layer in the walkway, so as not to overwhelm the smaller area.
The job took the two-man crew a day’s worth of cutting out of the week spent installing the project in order to be sure everything lined up square and even. Landscaping beds were also added as part of the project. Limestone boulders provide a decorative accent that helps transition the hardscape with the surrounding areas.
Installing a permeable paver job correctly involves far more than just paver selection and placement. A project’s water holding capacity and proper drainage are primary concerns.
The idea behind a permeable paver system is to allow movement of stormwater through the pavement surface and into a base or subbase reservoir capable of holding excess runoff. From there, the water is allowed to disperse gradually to the ground. This facilitates groundwater recharge and acts as a filtering device to remove surface water impurities, thus maintaining surface and groundwater quality. The DNR specifies rigorous performance standards, including infiltration rate, surface clogging capacity, and surface cleaning efficiency. Many of the design standards are also regulated.
“You have to consider that it’s a system, not just a paver type,” explains County Materials representative Soren Nelson. “If you don’t construct the system properly or think you can put in a different aggregate, you’re not going to get the proper results. We’re really educating our customers about it. We now have a project checklist for quality control to make sure the entire system is going in properly. We have little bags of the proper aggregate that we leave on-site so contractors can recognize what should be going in and compare it to what the truck delivers. If you do it right, you’re not going to have any problems.”
Exact design specs depend on site conditions, including soil type, expected maximum rainfall and drainage considerations. For this project, the crew had to excavate a deeper base, creating a 2-foot clear stone reservoir to contain the water. The base layers included 12 inches of 2-inch to 3-inch clear stone on the bottom, topped with 12 inches of 3/4-inch clear stone, and a final additional inch of smaller, 1/2-inch clear stone gravel on top. No fines were included in order to facilitate drainage. “You can’t use fines. It’s just going to plug it up,” says Stumpf.
The crew also installed a drain tile system to prevent backup. During rain or snow melt, the area under the drive fills with water, then disperses slowly to the lake through the tile system. In the process, it removes impurities and sediments that could compromise lake water quality. The system is designed to comply with DNR regulations that require the runoff reservoir to drain completely within 72 hours of a heavy rainfall.
Overcoming installation challenges
The narrow one lane, two-way road that the home sits on presented some challenges during construction. The biggest challenge involved the coordination of gravel deliveries.
Delivering the material on that road required careful communication between crew and driver. Once the gravel was on-site, it couldn’t be left sitting but had to be removed and put into place without delay.
The crew worked hard to keep traffic disruption to a minimum. They put up working signs, and made sure to get all equipment and material off the road as quickly as possible.
The finished driveway measures 1,300 square feet, allowing the couple ample room to access their garage. The entire project was installed in one week in August 2013. So far, the permeable paver system is performing as expected.
Additionally, the project has been recognized with two major hardscape awards. It received the Gold Award for Best Permeable Paver Residential Application in the 2015 Wisconsin Masonry Alliance Excellence in Hardscape competition. It also received national recognition as an Award of Merit winner in the 2015 National Concrete Masonry Association (NCMA) and Interlocking Concrete Pavement Institute (ICPI) Design Awards of Excellence.
Not surprisingly, the owners of the project are thrilled. This project successfully meets permeability standards, while at the same time delighting them with its function and beauty.
Read more: A Lakeside Permeable Paver Driveway via Turf Magazine