Amrit Sarovar and village ponds
Keep water in community ponds through the summer.
- Amrit Sarovar ponds
- Gram panchayat tanks
- Livestock watering ponds
RESEARCH PARTNERSHIP / 12
Field provenDelivered by Rispri Labs
Floating evaporation cover.
Keep the water you stored.
Rispri Labs delivers floating panels with a reflective, water-repellent surface that sit on ponds, lakes and reservoirs and stop the sun from boiling off the water you worked to store. Up to 95% less evaporation in field use, and no chemicals on the water.
RESEARCH TO REALITYRispri Labs research collaborations
What it means for you
Less water lost to the sun.
Up to 95%
less water lost to evaporation where the cover sits, in field use.
8–10 °C
cooler than the surroundings: the panel surface reflects the sun.
No chemicals
on the water. The cover is physical, not a film or additive.
Performance
A cool, dry lid on open water.
In the dry months a pond can lose a large share of its stored water to evaporation, often more than is drawn from it. Floating panels block the sun and the wind at the surface. Their reflective coating keeps them cool, and their water-repellent finish sheds water instead of soaking it up.
- 95%
- Reduction in evaporation under the reported field conditions
- 87%
- Solar reflectance of the panel surface
- 8–10°C
- Panel surface below the surrounding temperature
- 126.5°
- Water contact angle, up from 56.3° on an untreated surface
Figures are field and test data, including a field study at Kondiwade, Karjat. Every pond pilot runs beside an uncovered control, so the saving is measured on your own site.
Challenge and response
The problems this solves.
- 01The challenge
Ponds dry up before the rains, after all the work of building or desilting them.
How we solve itA floating cover keeps stored water in the pond through the hot months.
- 02The challenge
Open water heats up in the sun and evaporates fastest exactly when water is scarcest.
How we solve itReflective panels stay 8–10 °C cooler than their surroundings.
- 03The challenge
Chemical films and additives raise worries about drinking water, fish and livestock.
How we solve itNo chemicals go on the water; the cover is a physical barrier.
- 04The challenge
Savings claimed by suppliers are hard to check.
How we solve itEach pilot runs beside an uncovered control, so you see the saving measured on your site.
How it works
The process, step by step.
- 1
Survey
We measure the water body, its depth, inflows, use and local weather.
- 2
Cover
Floating panels with a reflective, water-repellent surface are laid on the water.
- 3
Reflect
The surface reflects 87% of sunlight and stays 8–10 °C below its surroundings.
- 4
Measure
Water level under the cover is tracked against an uncovered control on the same site.
Use cases
Where a floating evaporation cover delivers.
Farm ponds in dry districts
Save stored rainwater for the crop that needs it.
- Farm ponds
- Drip irrigation storage
- Farmer producer organisations
Industrial raw-water reservoirs
Cut make-up water bought or pumped to refill storage.
- Raw-water reservoirs
- Treated-water holding ponds
- Fire-water storage
Municipal water storage
Reduce losses from open storage in towns.
- Town reservoirs
- Service ponds
- Open storage tanks
Measured against a control
Every pilot keeps an uncovered area as the baseline.
- Same pond, same weather
- Level loggers on both areas
- Saving shown in litres
Water quality checked
Our NABL-accredited laboratory tests the water before and after.
- Drinking-water parameters
- Irrigation suitability
- Seasonal monitoring
Comparison
How it compares.
| Factor | Open pond / chemical film | Rispri solution |
|---|---|---|
| Evaporation loss | Full exposure to sun and wind | Up to 95% lower where covered |
| Chemicals on the water | Films and additives in some methods | None |
| Surface temperature | Water heats in direct sun | Panel surface 8–10 °C below surroundings |
| Water-repellence | Not applicable | Contact angle up to 126.5° |
| Proof of saving | Estimated | Measured against an uncovered control on site |
Standards and regulations
Designed around the rules that apply to you.
We design each system to meet your consent conditions and the regulations for your sector, and our laboratory reports against them.
- Mission Amrit SarovarNational mission to build and rejuvenate ponds in every district.
- Jal Shakti Abhiyan: Catch the RainCampaign for water conservation and rainwater storage.
- National Water Policy, 2012Framework for conserving and managing water resources.
- IS 10500:2012Drinking water specification, where stored water is used for supply.
Industries served
Built for the sectors that need it most.
- Pond and lake rejuvenation
- Gram panchayats
- Agriculture
- Industrial water storage
- Municipal water supply
- Smart water management
Why Rispri
Proven technology. Industrial delivery.
Field-proven technology
A proven, field-tested technology from our research collaborations with IIT Bombay, IIT Kharagpur and ICT Mumbai.
Tested on your stream
Our accredited laboratory characterises your water or waste before design and verifies results after.
Engineering since 1999
The team that builds ETPs, STPs and ZLD plants across India takes each solution from pilot to full scale.
One accountable partner
Design, supply, installation, commissioning, operation and testing under one contract.
Questions
Frequently asked questions.
What is a floating evaporation cover?
It is a layer of floating panels laid on a pond, lake or reservoir. The panels have a reflective, water-repellent surface that blocks sun and wind at the water surface, so far less of the stored water evaporates.
How much evaporation does it save?
Up to 95% reduction in evaporation under the reported field conditions, in a field study at Kondiwade, Karjat. The saving on your pond depends on the climate and how much of the surface is covered, so we measure it in a pilot.
How do you prove the saving on my pond?
Every pond pilot runs beside an uncovered control on the same site. Water levels in both are tracked through the season, so the saving is measured, not assumed.
Does it put chemicals in the water?
No. The cover is a physical layer of panels. Nothing is added to the water.
Why does the cover stay cool?
The panel surface reflects 87% of sunlight and stays 8–10 °C below the surrounding temperature, so it does not heat the water below it.
What does water-repellent mean here?
The coating raises the water contact angle to as much as 126.5°, from 56.3° on an untreated surface. Water beads and runs off instead of spreading over and soaking the panel.
Can it be used on drinking water storage?
Yes, since nothing is added to the water. Our NABL-accredited laboratory tests the stored water against IS 10500 before and after covering.
Is the technology proven?
Yes. The floating cover is a field-proven technology, tested in field conditions in Maharashtra. Every project still starts with a pilot beside an uncovered control on your own water body.
Which water bodies is it for?
Amrit Sarovar and village ponds, farm ponds in dry districts, industrial raw-water reservoirs and municipal water storage.
Research partnerships
More solutions from our partnerships.
THE NEXT STEP
Prove it on
your own pond.
Tell us about your pond, lake or reservoir. We will survey it, recommend a cover area and run a pilot beside an uncovered control.
Request a pilot