How potable water need not be wasted on BBMP parks and home gardens

According to a recent Indian Institute of Science-Bengaluru Water Supply and Sewerage Board (IISc-BWSSB) collaborative study, groundwater table on the outskirts of the city has fallen by at least 10 to 15 metres this year, and the situation may worsen during peak pre-monsoon months of March and April. This triggered the BWSSB to recently announce a ban on using drinking water for non-essential activities as the city is gearing up for a scorching summer.

The ban, effective immediately, prohibits the use of potable water for gardening, car washing, swimming pools, and construction. The BWSSB said that violators would face a ₹5,000 fine, with an additional ₹500 daily for repeat offenses. Amid the BWSSB’s ban, the Bruhat Bengaluru Mahanagara Palike (BBMP) recently announced that it would be using non-potable water for all its parks around the city. 

Treated water for parks 

A couple of days ago, during a meeting at the BBMP head office, the BBMP chief announced that the BBMP plans to acquire treated sewage water from the BWSSB to maintain its 1,280 parks across Bengaluru. Chief Commissioner Tushar Giri Nath directed officials to submit a report on conditions of borewell in BBMP-managed parks and called for immediate water supply arrangements at parks that had partially working or dried up borewells. 

“With summer approaching, adequate water supply is crucial for maintaining parks, lakes, and median plantations. Officials have been instructed to assess the exact water requirement, and the number of tankers needed and make the necessary arrangements at the earliest,” Giri Nath said. 

Speaking to The Hindu, Chandrashekhar M.R., Deputy Director of BBMP’s Horticulture Department, said that the BBMP is coordinating with the BWSSB to map parks to the nearest sewage treatment plants (STPs) for efficient water distribution. “The BWSSB has asked the BBMP’s Horticulture Department to assess demand, and we will be giving the report to them within a week. Based on our report, the BWSSB will map parks to STPs and supply water. As of now we have identified around 120 parks that need immediate attention and mapping to STPs. However, we will have the complete data of parks that need supervision and connection to treated water within a week’s time.” Chandrashekhar added that along with the parks, the treated water from STPs will also be used to water plants, bushes and trees on medians and pavements on the roads.  

Rudraiah M., a regular walker at a park in B.T.M. Layout, said that it was an appreciable move. “Last summer we noticed that parks around the area went very dry. There was a shortage of water for many residents in the area, as borewells had dried up. Watering parks was not even an option due to the shortage. Using treated water will help save water for human consumption and also contribute to ground water levels,” he said.

However, Raghu S., a resident of Thalgatpura, cautioned that water must be treated rightly or could cause discomfort to regular walkers. “We used to use treated water for the garden area of our apartment for a long time. However, the stench was really bad, and we were forced to stop. This was because our STP could treat sewage water only to an extent. The BBMP or BWSSB must make sure the sewage water is treated well,” he argued.   

Sushma Rao’s home garden that uses used water.
| Photo Credit:
HANDOUT E MAIL

What home gardeners do

While the BBMP is gearing up to use treated water in water parks, home gardeners from around the city said that they have been using innovative methods and using recycled water for their gardens.

“We have found an innovative way to repurpose around 600 litres of RO wastewater daily which we use for gardening and other purposes, and have stuck to the method since,” said Rohini Ghose, secretary of the Aristocrat Apartments association in Kasturinagar. “Being an older apartment complex, installing new pipelines wasn’t feasible, so we conducted a survey last summer and discovered that at least 70 of our 145 RO units could collectively generate about 10 litres of wastewater each day. To make collection easier, we provided residents with 10-litre jerry cans, which they fill and place outside their homes. The water is then transferred into two 200-litre drums fitted with taps and a hose for practical use in car washing, mopping, gardening, and even the swimming pool. We had a lab test confirming that our water quality, including RO reject water, meets WHO standards, allowing us to safely integrate it into our daily needs apart from drinking and cooking,“ she explained. 

Sushma Rao a resident of Poornapragna Layout, said that her family uses used water for their gardens. “When we wash vegetables, fruits and non-greasy utensils without soap, we do not let the water go down the drain through the sink. Most of the water is collected in a tub, which is later used for watering plants in our garden. The water used for cooking or boiling rice, lentils or vegetables is also collected in the same tub, which is also rich in nutrients and helps the plants grow better,” she explained. Sushma said that her family also has a rainwater harvesting system with two tanks, which helps them restore their ground water levels throughout the year, and there is hardly any shortage during the summer.

Ananya Iyer, a resident of Jayanagar, shared how her family has found a practical way to use non-potable water for their garden. “We have placed a bucket near our kitchen sink to collect water used for rinsing vegetables, fruits, and pulses. Instead of letting it go down the drain, we store it in a large bucket and use a small pump to distribute it to our garden plants,” she explained. Ananya added that they also collect RO reject water in a drum, which is later diluted and used for watering hardy plants like shrubs and trees. “Cauvery water is strictly used in our house only for drinking. These simple steps have helped us reduce wastage and keep our garden thriving without depending entirely on fresh water,” she said.