Permeable Pavement
The smartest drainage system
is the one you walk on.
Traditional hardscape surfaces shed water. Permeable surfaces absorb it. PICP — permeable interlocking concrete pavement — manages stormwater at the point of impact rather than routing it off the edge of a surface and into your yard, your neighbor's yard, or the municipal stormwater system.
LP designs PICP systems with properly sized open-graded bases, underdrain routing, and overflow protection — because a permeable surface without a designed base is just a paver with wide joints. We've been installing permeable hardscape systems across Post Falls, CDA, and Kootenai County since 2005.
Hardscape that solves drainage
instead of creating it.
Manage Runoff at the Source
Permeable pavement captures and infiltrates stormwater where it falls rather than routing it off-site. This is the most effective stormwater management approach — reducing peak flow, eliminating pooling, and recharging groundwater. For properties with drainage problem areas, PICP is a hardscape solution that also solves the drainage problem.
Reduces Pooling and Wet Areas
Patios and driveways that pool water after rain are candidates for permeable solutions. Rather than routing runoff off the edge of a surface, PICP manages it below the surface. Post Falls and CDA properties with clay soils benefit most — permeable surfaces slow the runoff that clay soils can't absorb fast enough.
Aesthetic Quality of Standard Pavers
PICP looks identical to standard interlocking pavers from above. The open aggregate joints are narrow enough to be visually indistinct from standard paver joints. Homeowners get the design flexibility of a full paver patio with the stormwater management benefit of a permeable system.
Potential Stormwater Compliance Tool
For new construction and developments subject to Kootenai County or municipal stormwater requirements, PICP and pervious concrete can satisfy retention requirements and reduce the need for traditional stormwater ponds or detention basins. LP works with project engineers to document system performance.
Permeable pavement that manages stormwater across North Idaho.
"Our PICP driveway in Spirit Lake handles all the runoff from our roof and doesn't create puddles in the yard. The engineering was spot-on."— Tom B., Spirit Lake, ID
"LP designed our permeable patio in Hayden to meet county stormwater requirements. It looks great and actually helps with drainage instead of making it worse."— Karen M., Hayden, ID
"The open-graded base under our PICP walkway in Sandpoint really works. No more water pooling and the surface stays clean."— Mike S., Sandpoint, ID
"Our permeable driveway in Coeur d'Alene has eliminated the runoff issues we had before. LP's engineering made all the difference."— Jennifer R., Coeur d'Alene, ID
From surface to subsurface:
every layer engineered.
PICP — Permeable Interlocking Pavers
Permeable interlocking concrete pavement (PICP) uses open-jointed concrete paver units filled with washed aggregate rather than polymeric sand. Water passes vertically through the joints into an open-graded aggregate base reservoir below. The base stores water temporarily and allows it to infiltrate into native soil or drain to a designed outlet.
Open-Graded Aggregate Base Design
The performance of PICP depends entirely on the open-graded base beneath it. LP specifies base depth, aggregate gradation (typically ASTM No. 57 or No. 8 stone), and geotextile separation layers based on the site's soil infiltration rate. The base is the reservoir — it must be sized for the drainage area and storm event it needs to manage.
Overflow & Outlet Engineering
PICP systems need a designed overflow outlet for rain events that exceed the base reservoir capacity. LP engineers overflow inlets, perforated underdrain pipes, and outlet routing as part of every PICP system — so when a 100-year event exceeds the base capacity, water has a designed path out rather than backing up.
Pervious Concrete Applications
Pervious concrete uses a gap-graded mix with minimal fine aggregate, creating a porous slab that allows water to pass through. Less design flexibility than PICP (no pattern or color variation), but lower cost for large-area applications like parking pads, service areas, and commercial applications where stormwater compliance is required.
Stormwater Compliance Support
Some Kootenai County developments and commercial properties require stormwater management as a condition of development permits. PICP and pervious concrete can satisfy on-site stormwater retention requirements. LP coordinates with project engineers to specify systems that meet the required retention volume and discharge rate targets.
Maintenance & Long-Term Performance
Permeable surfaces require periodic vacuuming or pressure washing to remove fine sediment that accumulates in joints and surface voids over time. LP provides maintenance guidance and can perform scheduled maintenance service. Systems installed over clay-heavy soils with low natural infiltration rates require more active outlet management.
Permeable hardscape across North Idaho.
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