Case Study: Landscaping Drainage Upgrade in Khorda, Odisha

Product used: Ocean Drain Cell, 30 mm
Quantity installed: 1,030 sqm
Location: Khorda (Khurda district), Odisha

For a landscaping project in Khorda, Ocean Non Wovens supplied and installed 1,030 sqm of Ocean Drain Cell 30 mm as the main drainage and protection layer beneath the landscaped zones. The site needed a sub-surface drainage layer that could take monsoon inflows without letting water pond under planters, lawns and walkways.

Why landscapes fail when drainage fails

Most landscape failures come from water with nowhere to go, rather than from the wrong plants or paving. When water is trapped under planters, lawns, walkways or podium landscapes, the same problems follow:

• waterlogging and root stress
• algae and slippery surfaces on pavers
• foul odour in planters from anaerobic conditions
• soil fines migrating into drains and choking outlets
• waterproofing membranes stressed by hydrostatic pressure

Khurda district’s normal annual rainfall is about 1,408 mm, roughly three-quarters of it in the June to September monsoon (ICAR district contingency plan). When rain arrives in intense spells, a landscape needs a drainage layer that collects water quickly and moves it sideways to discharge points before it ponds and builds pressure.

Site challenges

Challenges that commonly show up on landscaping projects in Odisha:

1. High inflow during monsoon months (June to September), which causes short spells of saturation and waterlogging.
2. Fine soils and silt, which clog aggregate-only drainage layers over time if filtration is not designed in.
3. Limited depth in planters, podiums and walkways, where thick gravel layers are impractical.
4. Maintenance access: if outlets cannot be reached, nobody can flush or inspect the system later.

What a drain cell does

A drain cell (also called a drainage cell or drainage board, or a geocomposite drainage layer when a filter fabric is bonded to it) is a moulded plastic layer with open voids. In landscaping it:

• creates void space for rapid water collection
• carries water in-plane (within the layer itself) towards outlets
• replaces thick gravel layers, saving depth and dead load
• gives a consistent, factory-made drainage path

A 30 mm profile is commonly used in podium landscaping, planters and roof gardens because it gives useful void volume without taking up much depth, is easy to lay, and protects the layers next to it. Final performance still depends on the whole system: filtration, outlet design, falls and maintenance.

What decides drainage performance

1. Compressive strength figures need a test condition

Many datasheets quote compressive strength, often by ASTM D1621, a method written for rigid cellular plastics and frequently modified. Two datasheets are not comparable unless the test conditions match. What matters on site is that the layer keeps enough void space under load after installation, wetting and time, so retained thickness and retained flow under the expected load are more useful than a single peak strength. Selection on this project focused on consistent drainage paths and protecting the system from clogging and outlet failure.

2. Drainage capacity is measured as transmissivity

Transmissivity is the flow a drainage layer carries within its plane under a given normal load and hydraulic gradient, measured by ASTM D4716. Two products may look alike, but the one that retains more transmissivity under load will handle a monsoon surge better.

3. Filtration prevents clogging

Fines migrate in landscaping. Once they fill the voids, the drainage layer holds water instead of discharging it. Common causes:

• no filter geotextile where soil sits on the drain cell
• poor overlap detailing at joints
• outlets without silt traps
• soil entering at planter edges from rain splash or irrigation

Execution on this project emphasised clean interfaces, wrapping and termination where required, and discharge points that stayed working and inspectable.

4. Roots and maintenance access

Roots grow towards moisture, so a leaking or clogged outlet attracts them. Many landscapes also hide outlets that become unreachable after finishing, and nobody maintains what nobody can reach. The project therefore placed discharge points logically, provided clean-outs or inspection access where feasible, and avoided sealed systems that cannot be flushed.

Installation sequence on site

• Subgrade preparation: falls checked towards the discharge direction; sharp protrusions and debris removed to prevent puncture.
• Placement of Ocean Drain Cell 30 mm: laid across the planned landscaping zones, 1,030 sqm in total, aligned so in-plane flow runs efficiently towards the outlets.
• Joints and edges: joints kept tight and consistent; terminations detailed to stop soil entering at the edges, where drainage systems usually fail first.
• Outlets: checked for an uninterrupted flow path and kept clear of cement slurry and soil during construction.
• Cover and landscape build-up: placed carefully so construction traffic did not crush, displace or contaminate the drainage voids.

Intended results

The Ocean Drain Cell layer at Khorda was designed to:

• remove excess water quickly during heavy rain
• reduce the waterlogging that damages plants and finishes
• limit hydrostatic pressure near waterproofing and structural interfaces
• keep the landscape performing consistently through monsoon cycles

Checklist for landscaping drainage in high-rainfall regions

• Don’t accept compressive strength at face value unless the test condition and retained performance are stated.
• Ask for transmissivity test data (ASTM D4716).
• Design filtration to keep fines out.
• Keep outlets accessible and protect them during construction.
• Treat drainage as a system, not a single product.

Ocean Non Wovens

For podium landscapes, commercial planters, walkways or other landscaping in high-rainfall areas, Ocean Non Wovens can help with geosynthetics selection, supply and site guidance. Ocean Drain Cell 30 mm is made for sub-surface drainage, and the team can help match detailing, discharge planning and execution to the site conditions. Contact Ocean Non Wovens to plan a drainage layer for your next project.