Geocellular soakaway

Types of geocellular soakaway

A geocellular soakaway is a type of stormwater management soakage structure that uses plastic geocellular cells to control and manage the infiltration of surface runoff into the ground. Geocellular soakaway can be designed for attenuation (temporary storage) to reduce peak discharge into receiving drainage to avoid downstream flooding and for infiltration (gradual soakage into the ground) to recharge groundwater and promote the natural hydrology of the area.

• Infiltration soakaways

  As the name suggests, these soakawys allow the storm water in them to completely infiltrate through all the plastic cells into the underlying permeable ground and then into the plastic a recharge for groundwater, which is continuous throughout the year. They are mostly built in areas with good absorbing capabilities of soils and high permeability to reduce surface runoff and allow storm water to drain naturally to the ground.

• Attenuation soakaways

  The main function of the attenuation soakaway is temporary storage of storm water within storm water management cells before the slow meal infiltration is facilitated once the runoff levels have receded. They are made mostly in areas that cannot accommodate high inundation levels and are effective in minimizing flood incidences and surface water within the drainage system by allowing planned storm water disposal and infiltration.

• Combined soakaways

  Combined soakaways have both attenuation and infiltration features built into them, aimed at temporary storing storm Water while enhancing its infiltration into the permeable subsoil. These plastic soakaway pits are useful in balancing the objectives of flood control and groundwater recharge and are often installed in areas with varied soil permeation characteristics.

Design of geocellular soakaway

Soakaway design should be done based on the following factors: the amount and intensity of rainfall expected, the soil types in the area and how permeable they are, how much land will drain into the soakaway, and if there are any nearby buildings or utilities.

• Size

  Soakaways should be large enough to allow all the rain from the area around them to soak into the ground without overwhelming them. The size maybe be determined by rainfall amounts and the type of soil in the area. Calculating a soakaway's size will give it a better chance of preventing flooding.

• Materials

  Plastic soakaway crates are made from strong, weatherproof plastic that can last a long time. The crates have holes in them to let water soak through easily. A geotextile fabric is used to cover the outside so soil or debris can't clog the soakaway system. Then, a layer of large gravel is used to help move water through the soakaway and into the ground.

• Installation considerations

  When installing the soakaway, around the crates should be at least 200mm deep with a layer of large stones. The top of the soakaway should be covered with a geotextile membrane. Local building drainage standards should be checked to make sure the soakaway meets requirements.

• Sustainability

  Geocellular soakaways are sustainable features because they help manage surface water and allow rainwater to soak into the ground naturally instead of running off right away. This helps recharge groundwater. They are also called SuDs soakaways.

Specification & Maintenance of geocellular soakaway

Geocellular soakaway specifications

• Soil percolation rate: The rate that water soaks into the ground at the soakaway site.
• Soakaway size: How large the soakaway needs to be to handle rain in the area without overflowing.
• Required materials: What materials to use for the soakaway, like plastic crates, gravel, and fabric.
• Stability reinforcements: Any added features to keep the soakaway from breaking apart during heavy rains.

Maintenance suggestions for geocellular soakaway

• Routine soakaway checkups: At least every 6 months, inspect the soakaway for issues. Look for damage, blockages, or settling.
• Cleaning tips: Clear any debris from the top and edges of the soakaway. Do not remove or change the geotextile cover.
• Test soakaway function: After heavy rains, check that water drains properly through the soakaway cells. There should be no standing water.
• Device maintenance: If there are any soakaway accessories like pipes or catchment chambers, check and clean them as needed.
• Damage repairs: Fix any cracks, breaks, or other issues found during inspections.

Scenarios for geocellular soakaway

Geocellular soakaway situations:

• Residential projects: In houses and neighborhoods, soakaways manage roof and yard rainwater. They keep water from pooling or flooding.
• New housing areas: For large housing developments, soakaways control rain from many homes at once. They prevent drainage problems.
• Paved places: At parking lots, sidewalks, and other hard surfaces, soakaways slow down rainwater.​
• Roadside designs: By roads and highways, soakaways stop runoff from getting onto the road itself. This helps keep travel safer.
• Green areas: In parks and sports fields, soakaways let rain soak into the ground and water plants.

Important factors for geocellular soakaway use:

• Soil type: The ground below needs to be able to absorb water easily. Clay or sandy soil works well.
• Rain amount: Enough rain is needed to fill the soakaway cells and slowly release the water.
• Nearby buildings: Soakaways must be far enough from homes, fences, or roads to avoid damage.
• Space available: Enough area is needed for soakaways to fit comfortably without feeling cramped.
• Surrounding land: The land around the soakaway should be level so water doesn't drain away too quickly.

Selecting geocellular soakaway

• Ground conditions

  Soil analysis is performed to see if the earth underneath will allow water to drain properly. Tests on the ground help pick the right soakaway system. Things like whether the soil is sandy or clay-like and how close the water level is to the surface are important.

• Rainfall and runoff prediction

  Calculating expected rain amounts and how much rainwater ends up at the soakaway site is key. The soakaway must manage both the roof and yard rainwater for individual homes. Models can estimate any excess rain that falls in during intense storms.

• Location requirements

  Local rules must be followed when putting in a soakaway. Some places have specific policies about managing drainage or getting rid of stormwater. Soakaway systems should also be put far enough away from buildings or fences to avoid harm.

• Types available

  A variety of soakaway systems are on hand. Plastic crate versions are easy to install and don't take up much room. Stone-filled types are stronger, but harder to set up. Each one has pros and cons depending on the situation.

• Costs evaluated

  The expenses to install and maintain the soakaway must be considered. Though they take longer and cost more at first, plastic crate soakaways are cheaper to care for later. Brick and mortar options are more expensive to start but last longer with minimal ongoing costs.

Q&A

Q1: What is a geocellular soakaway used for?

A1: Geocellular soakaways control and manage stormwater. They store and gradually release rainwater to prevent flooding.

Q2: How does a geocellular soakaway work?

A2: The soakaway plastic cells hold stormwater, and then the ground absorbs it slowly. This allows rain to soak into the earth rather than running off.

Q3: What materials are geocellular soakaways made from?

A3: Geocellular soakaways are made from strong, weatherproof plastic interlocking cells. A layer of large gravel helps drainage.

Q4: Do geocellular soakaways need maintenance?

A4: They require lower maintenance than other options. Clearing debris from the top and inspecting it occasionally is all that's needed.

Q5: Why are geocellular soakaways important?

A5: They reduce flooding risk, help recharge groundwater, and manage rainwater sustainably in urban areas.