Rainwater Harvesting System at Bute Park

Bute Park Grows over 350K plants each year for the Council’s Parks Department. To keep all these plants healthy, we use a significant amount of water for irrigation. Currently our water is fed by mains into a large storage tank before passing through a pump to the glasshouses.

New Scheme:

We have successfully bid for monies from One Planet Cardiff to install a scheme to collect and filtrate rainwater which falls on the nursery glasshouses to irrigate the plants we grow. Calculations based on rainfall from 2018-2022 estimate that there is a potential to collect 1738.6 m3 of water annually.

We propose to:

Install a rainwater collection tank

Replace and install new pipes on existing glasshouses to divert rainwater into new collection tank

Install a system to transfer water from new collection tank to existing water storage tank

Installation of a Slow Sand Filter to sterilise rainwater before it is used for irrigation

Carbon Reduction and OPC Benefits:

The main ecological benefit offered using rainwater collection systems is the reduction in the use of mains water which means that less water will need to be artificially drawn from the environment. Mains water is pumped long distances and heavily treated to make it potable.

One of the other ecological benefits of rainwater harvesting systems is that they lessen the load placed upon drainage systems.

Other Benefits:

Significant savings in water bills.

Could be used as an educational tool for water use as Nursery is the same site as the Bute Park Education Centre.

Project could be used as a trail to see if similar systems could be used on other council buildings with large surface area leading to significant rainfall collection potential.

Filtration system could lead to water freer of contaminants leading to better plant health and a reduction in chemicals used.

Location of the project: Bute Park, Cardiff

Crop: Ornamentals

Electrical grid parameters: 230–400-volt 50 Hz

Investigate options to collect rainwater from two glasshouses for potential use in irrigating all glasshouse crops on site.

Existing rainwater runs to waste outlets below nursery site

Existing irrigation water tank supplied with mains water

Based on data retrieved from the Bute Park weather station, it has been calculated that an average of 145 m3 of rainfall is available per month for collection from Glasshouses 4 and 6 (367 m3 maximum). Pro-rating these figures, daily indicative amounts of 4.8 m3 (average) to 11.8 m3 (maximum) have been used to size an appropriate collection and filtration tank size.