The Benefits of Rainwater Harvesting for Your Lawn and Garden
In the UK, we spend plenty of time wishing the rain would stop. Then summer arrives, the lawn starts drying out, and suddenly we wish we had kept some of it.
That is where rainwater harvesting comes in.
Rainwater harvesting involves collecting and storing rainwater that falls on roofs and other appropriate surfaces for later use. It can range from a simple setup like a water butt attached to a shed downpipe to a larger system that stores significantly more water.
For your lawn and garden, this involves efficiently utilising water that would otherwise be wasted down the drain.
What Are the Benefits of Rainwater Harvesting?
The main benefit of rainwater harvesting is providing a personal water supply during dry spells and hosepipe bans.
But there are other advantages too.
Rainwater harvesting can:
- Reduce your reliance on mains water.
- Reduce rainfall immediately entering drainage systems.
- Provide naturally soft water for garden use.
- Make better use of rainfall throughout the year.
- Help you prepare for increasingly changeable weather.
For those committed to maintaining their lawn, the main advantage is straightforward: you can gather water during times of abundance and use it later during shortages.
Why Is Rainwater Good for Your Lawn?
Rainwater is naturally gentle and usually has fewer dissolved minerals than mains water.
Since your lawn already benefits from rainfall, rainwater harvesting lets you capture and store some of this water for when your grass needs extra moisture.
This approach is especially helpful during extended warm, dry spells. Instead of losing rainfall to runoff, you’re saving some of it for future use.
How Much Rainwater Could You Actually Collect?
Probably more than you think, every roof acts as a collection point.
Your house, garage, shed, or greenhouse can all channel rainwater into storage. Even small roofs can gather thousands of litres annually.
The amount you can store depends on the size of the collection area, local rainfall levels, and the capacity of your water butt or rainwater harvesting system.
A single small water butt will fill quickly during extended rain. If space allows, connecting multiple units can greatly boost your storage capacity.
Can Rainwater Harvesting Save Mains Water?
Yes. Collecting and using one litre of rainwater in the garden replaces one litre drawn from the mains supply.
This matters because tap water is collected, treated, and transported to ensure it’s safe for drinking, whereas your lawn doesn’t need drinking-quality water.
Thus, using stored rainwater when possible is a sensible choice. If your water is metered, cutting back on mains water usage can also help lower your water bill.
Don’t Waste Heavy Rain
Rainwater harvesting offers an interesting perspective on Britain’s weather patterns.
Sometimes, the issue isn’t a lack of rain but an excess. During heavy downpours, water rapidly flows from roofs, patios, and other hard surfaces into drainage systems.
By capturing some of this runoff in a water butt or larger tank, you can store it temporarily.
While a single household water butt can’t prevent local flooding, collecting rainwater helps reduce immediate runoff and provides a valuable water source.
Save Winter and Spring Rain for Drier Weather
A bit of forward planning can be beneficial here.
If rainfall occurs regularly, your lawn might not need extra watering. The real advantage is saving some water for the hotter months.
During dry periods, you can use stored rainwater in the most effective areas to maximise its benefits.
Think particularly about:
- Newly seeded areas
- Recently renovated lawns
- Dry or exposed sections
- Areas recovering from damage
- Lawns experiencing prolonged drought stress
You don’t always have to keep every square metre green all summer; mature lawns can recover well after drought.
However, when extra water is truly necessary, having a stored supply offers an added option.
Make Your Stored Rain Go Further
Collecting rainwater is just one part of the equation. Your soil must also be able to absorb and hold it.
Compacted or hydrophobic soil can cause water to run off instead of reaching the roots, meaning your stored rainwater might be lost.
Good soil structure, healthy roots, and proper moisture management enable your lawn to use every litre more efficiently.
Treatments like aeration can reduce compaction, and TruGreen’s Aqua Boost can enhance water movement and retention in the soil.
The goal isn’t just to provide more water but to ensure your lawn uses the available water more effectively.
How Should You Store Rainwater?
For a basic garden setup, start with a covered water butt linked to a downpipe.
Regularly clear gutters and filters of leaves and debris. Ensure your storage unit has a secure lid and proper overflow.
Water butts should be cleaned occasionally to prevent deterioration caused by organic buildup or stagnation.
If you’re planning a significantly larger rainwater harvesting system, especially one connected to household plumbing, consult a professional.
Is Rainwater Harvesting Worth It for Your Lawn?
If you have a suitable place to collect and store rainwater, it can greatly benefit your lawn care efforts.
It decreases your reliance on mains water by utilising rainfall that would otherwise drain away.
Most importantly for your lawn, it provides a reserve for times when natural rainfall is insufficient.
While we can’t control when it rains, we can improve how we manage that water once it arrives.
If you already have a rainwater harvesting system, use it wisely. Combine efficient water usage with healthy soil, deeper roots, and professional lawn care to maximise each litre.
Frequently Asked Questions
What is rainwater harvesting?
Rainwater harvesting is the collection and storage of rainfall from surfaces such as roofs. The stored water can then be reused, including for watering lawns and established garden plants.
Is rainwater good for lawns?
Yes. Rainwater is naturally soft and can be used to provide additional moisture to lawns when conditions become dry.
Does rainwater harvesting save water?
It reduces your use of treated mains water by allowing you to use stored rainfall for suitable tasks such as garden watering.
Can rainwater harvesting help during dry weather?
Yes. Water collected during wetter periods can be stored for use when rainfall becomes less reliable, although the amount available will depend on your storage capacity.
Does collecting rainwater help with drainage?
Capturing roof water temporarily reduces the amount immediately flowing into drains during rainfall. The effect of an individual system is limited, but rainwater storage is a recognised way to manage runoff at the property level.
How can I help my lawn make better use of rainwater?
Healthy soil is essential. Addressing compaction, encouraging deeper roots and improving moisture movement through the soil can help water reach the rootzone rather than running away across the surface.
