How to Install a Basic Rainwater Harvesting System
A basic rainwater system can be used to supply seasonal rainwater for irrigation, vine spraying, rinsing of harvest bins, vehicle washing, and landscaping. This system consists of:
- a collection and conveyance system to collect rainwater from the roof and remove debris
- above-ground barrels or tanks to store the collected rainwater
- optional irrigation pumps to provide water pressure
The pH of rainwater may differ from groundwater or municipal water sources and may change when stored for longer periods of time. Wineries using rainwater for vine spraying should ensure that any pH changes will not impact the effectiveness of pesticides or fungicides.
Case Study: Basic Rainwater harvesting at Harwood Estates
Harwood Estate Vineyards implemented rainwater harvesting to improve their water security. Shallow topsoil in portions of their vineyard means the soil dries quickly and vines require watering during dry summer months. The ground water in the area has high sulphur content and trucking in water for irrigation is prohibitively expensive.
Harwood installed gutters to collect rainwater from roofs in a single location and a first-flush diverter and screen filters to remove debris. In order to minimize costs, they purchased inexpensive 1000 litres plastic totes. The totes are on wooden skids so additional storage capacity can be added by replacing full totes with empty ones as required with the use of a forklift.
The harvested rainwater is used to irrigate the vineyard, wash tractors, clean the crush pad, and as first rinse in tanks. The winery has found that water can be stored untreated in the totes for up to a month without significant impacts to the water quality. Although they have found that the pH changes over time so have refrained from using the rainwater for vine spraying.