Rainwater Harvesting


While the demand for potable water is constantly rising in urban centres, the supply of this resource faces a number of challenges. Therefore, rainwater  harvesting for non-potable purposes is a fast growing industry that mitigates this problem.

Our extensive experience in computer modeling and designing well-balanced water harvesting systems; based on the local meteorological and evapotranspiration data; unique characteristics of the collection area and estimated water requirements for irrigation or other uses; allows us to assist the clients in optimizing the size of the collection tank, maintaining good quality of the harvested water and significantly reducing the use of potable water.

Pawel Gradowski is also an ARCSA Accredited Professional certified by The American Rainwater Catchment System Association.


LASquare's selected recent projects with rainwater harvesting component

Rainwater harvesting / Residential pool  - Johannesburg

Design - 2021
Installation completed  - 2022

This project is located in the Johannesburg’s Observatory area. The outdated backyard with a large, old swimming pool and the narrow, dysfunctional patio had to be modernized.

The following were the key objectives for the new design:
• reduce the size of the pool from ±120.000 to ±50,000 liters
• redesign the backyard to provide a large, usable space for family gatherings
• increased privacy of the yard
• introduce rainwater harvesting measures allowing for collecting the runoff
from the large roof and the hard landscape area. Water will be used for topping-up the pool and for the new irrigation system for the garden
• add outdoor fire pit and braai (BBQ) area
• link the adjacent cottage building with the pool area

LASquare redesigned the backyard and assisted during the construction process. The existing pool has been rebuilt into two vital components: a new 3m x 11m swimming pool and a large, underground water storage that can harvest up to ± 75,000 liters of rainwater.

The new, rectangular pool is partially located inside the old structure and includes:
• a shallow(±0.5m) area for the kids
• a deeper (±1.8m to 3m) swimming area, which is protected with an underwater net
• an ‘infinity edge’ section with a catchment that doubles as a wadding area for small kids
• colour LED underwater lights and rope-lighting at the outside perimeter of the pool

The water storage area is divided into two sections. The larger chamber collects rainwater that is partially filtered via the gravel sump. From this chamber water goes through a sand filter and is collected in the second, smaller section. The double-filtered water is than used for the irrigation and the pool. Both underground, concrete tanks are covered with a new decking
that is built from the composite material. A section of the decking can be open to access both the tanks. A small water feature in the adjacent planter allows for monitoring the quality of the stored water. The gas fireplace eliminates the risk of ashes contaminating the pool. The new, raised planter edge provides ample sitting opportunity adjacent to the colorful vegetation.

   Download a PDF file for this project
  View a 1 minute construction film

KSB Pumps and Filters - Ekurhuleni

Design - 2022
Anticipated Construction - 2022

The goal of this project, located within the industrial area of Germiston in Ekurhuleni, aims at converting two outdated industrial structures into modern office buildings surrounded with an attractive landscape.

Some of the existing factory structures have been already demolished, leaving only selected steel structures and an industrial concrete floor on the ground. The existing structures will be incorporated into the landscape design, repurposing their functions into attractive and functional feature. The existing concrete floor will be partially removed and relocated within the site, creating room for soft landscape treatment.

A large water feature with three connected pools and a centrally located roofed gazebo, will provide an opportunity to the Client, who manufactures industrial pump and filter products, to display and promote some of their products.

A large, underground cistern has been designed for harvesting rainwater from the roofs of the buildings and all hard and soft landscaped areas. The collected and pre-filtered runoff will be used for landscape irrigation system; compensating evaporation loss in the water feature; for all pump demonstrations at a specially designated facility; and for selected uses at the office building.

The soft landscape at this site will consist of mostly indigenous plants that are drought resistant and provide attractive setting throughout the year.