Question

What are the potential upstream and downstream impacts of replacing the gravel parking lot with a tru-grid system? Please explain in detail

Answer 1

A permeable pavement system combines a series of plastic grids with a fill materials, such as gravel, limestone or sod, to create a durable parking surface that allows moisture to soak into the ground naturally. It is used as an alternative to conventional asphalt or concrete surfaces, which are expensive to install, prone to damage and require complicated drainage systems to control water from rainfall and floods.

Permeable pavement has become increasingly popular in municipalities with aging waste water systems, and it is often used where there is a need for permanent or temporary parking or roads. It can also be used for permanent parking, lawn parking, driveways and erosion control.

Here are some of the advantages that permeable pavement has to offer:

1. Easy Installation

Permeable pavement does not require expensive specialty equipment like asphalt or concrete surfaces do. For a permanent installation, the ground must be cleared of vegetation and graded, the layer of rock is installed as a base, similar to a concrete or asphalt installation. Then the grids are laid out, and trimmed to fit around any objects. The grids are pallet-sized and light enough to be carried by a single person, making it easy to cover large areas in a very short time. Once the grids are in place and locked together, they are filled with gravel or limestone, and compacted into a strong and durable surface. Due to the strength of the grids, heavy equipment can be used to dump, spread and compact the fill material with proper planning and coordination. Once the grids are filled, they are durable enough to accommodate almost any type of vehicle or equipment.

2. Durable

Once filled, permeable pavement is as durable as concrete or asphalt surfaces, and in many cases, even more durable. It can support heavy equipment such as wheel loaders, backhoes, fork lifts, dump trucks and 18-wheelers without a problem. Because it is a floating surface and has joints that make it flexible, it can move as the soil beneath it changes. Asphalt or concrete will tend to buckle when conditions like frost cause upheaval, or if the soil underneath is compacted or washed away. Permeable pavement will not crack due to expansion and contraction like concrete, and it is less likely to be damaged and form potholes, like asphalt.

3. Sustainable

The permeable pavement grids are made from environmentally-friendly recycled materials, which reduces the amount of waste in the system and reduces the energy required to acquire new materials. At the end of their lifespan, they can easily be recycled, further reducing their carbon footprint.

4. Low Cost

Asphalt and concrete can be expensive to install and require a large amount of labor. Permeable pavement is less expensive per square foot, and is much less labor-intensive. The fill materials can be obtained from local sources, reducing transportation costs, and because the paving grids are made from lightweight plastic, the shipping costs are kept to a minimum.

5. Can Be Temporary

Sometimes businesses need extra parking on a temporary basis, like during the holiday season or at large sporting events. Afterward, the space may need to be reclaimed for other uses. Permeable pavement can be the perfect solution for temporary parking. The grids can be laid down over a simple bed of gravel or reasonably flat soil, then filled with gravel or limestone to create a temporary parking area. Afterward, the grids can easily be removed and stored for the next time they are needed, and the fill material can be hauled away or reused elsewhere.

6. Can Be Used for Lawn Parking

The grids themselves, without fill, can be used for temporary lawn parking with lightweight vehicles, and by spreading the load out, the lawn incurs less damage and the grids can easily be removed and stored for later use. For permanent expansion parking at venues like fairgrounds or music venues, the grids can be installed with a base of rock, then filled with sod or soil and grass seed to provide a durable parking surface that looks like a regular lawn when it is not being used. It can be maintained with regular lawn equipment, and unlike dirt parking areas, it will not turn into a muddy mess after a rain storm.

7. Can Create Temporary Roads

Heavy equipment at construction sites or oil fields can cause damage to the surrounding soil, compacting it or creating ruts that make it difficult to traverse, especially after a rain storm. With permeable pavement, you can create temporary roads that protect the soil during construction or drilling operations. Afterward, the roads can be removed, and the site can be restored to almost original condition. With a bed of rock and gravel fill, the permeable pavement will be able to support the heaviest equipment, but can still be easy to remove.

8. Eliminates Costly Drainage Systems

With a conventional asphalt or concrete surface, the parking area must be crowned and have a system of storm drains and pipes to control water during rain or flooding events. This can significantly add to the construction costs of the parking area, and if the system is connected to a municipal waste water system, there may be extra costs and permits required to install the drainage system. Permeable pavement allows any water that accumulates to drain through the surface and into the ground. This helps to prevent flooding and allows any aquifers in the area to replenish naturally.

9. Can be Used for Erosion Control

In areas with loose soil, such as the arid southwest or on hills or slopes, permeable pavement can be used to retain soil and prevent erosion. Simply place the paving grids over the area that needs protection and fill it with gravel, or for a more natural look, soil and grass seed. It an also be used for landscaping purposes, to create walkways or decorative areas around trees or other structures.

Permeable pavement is an extremely versatile paving material and is a great value compared to asphalt or concrete. It creates a strong, durable surface that requires a minimal amount of maintenance, and it can be used almost anywhere.