DIY rainwater harvesting basin
Date:
Mar 12, 2025
Category:
Permaculture Tutorial
Tools:
Shovel
Why should you build a basin?
Lush vegetation that you can enjoy WITHOUT pulling from municipal water supply.
Harvest pristine water that is already falling onto your property, free of salts and full of micro-organisms that your plants will love.
Create an oasis for microorganisms, native flora and fauna, and you.
Mitigate flooding and all the headaches it brings.
Minimal maintenance for maximal return.
Rebuild the soil you live on.
Increase your property value $$$.
Recharge your regional aquifer.
Build a deeper connection between you and the patch of Earth you inhabit.
Respect for water.
Observe
Observe where the water naturally flows when it rains. Is it pooling in a spot you don’t want? Is it running off into the street? Is there water flowing in from a neighboring property? Where is the highest point on the property and where is the lowest point?
Tip: Use a map of the property (follow this tutorial), and draw out everything to organize your thoughts. Mark the direction that water is flowing on the site.
Where NOT to put a basin
Within 5 feet of your house (you don’t want water pooling at the foundation)
Above any underground lines, pipes, or cables (call your utility company locator at least three days before you plan on digging)
Above a septic drainage field or next to a drainage field if the water table is higher than 20’ (not common in arid environments)
In the middle of any major circulation paths (obviously)
Right next to the base of any established plants. As a general rule, dig at the edge of the existing plant canopy. You don’t want to harm the roots.
Mark the basin(s) boundary + overflow
Starting from the highest point on the property, mark the boundaries of the basin(s) and where they will overflow when full. In large rain events, the basins will fill up and you want to make sure you have a path for the water to overflow into another basin or off the property. The edge where the water overflows needs to be slightly lower. Don’t overthink it, you will have time to test and iterate as you observe how they function in rain events. Water moves from the highest point to the lowest point. Make your basins have rounded edges to reduce water erosion (water likes to make things round).
Dig!
Grab a shovel and dig down 6”-12”. The deeper it is, the more water it will carry. Try to make the base of the basin as level as possible. Make sure the overflow route edge is slightly lower to allow water to drain properly. To reduce erosion, where the edge of the overflow route loses soil, line the overflow route with rocks. Create gently sloped edges that are approximately 33 degrees.
Plant!
Take a hike! Observe what native plants are in your bioregion. Plants that prefer more drainage can go along the edge of the basin. Plants that prefer more water can be terraced along the edges (for deeper basins). Terraces can be stabilized with rock to reduce erosion. Grasses can go in the deepest part of the basin. If you don’t want to buy plants, you can buy a native seed mix and spread it along the edges of the basin before rain.
Mulch!
Do not skip this step! The goal is to create a sponge that absorbs rainwater and allows it to slowly sink into the soil. Local arborists will often deliver wood chips to your property for free. Wood chips are a great place to start. You can also use piles of leaves or tree branches as mulch. Mulch limits weeds and allows mycelium to proliferate which helps your plants be healthy.
Observe and iterate
Next time a big rain comes through, watch how the basins work. Where does the water go? Make corrections as needed.
________________________
References
Lancaster, Brad. Rainwater Harvesting for Drylands and Beyond. Rainsource Press; Revised Second Edition, 2019.
Watershed Management Group. "Build Your Own Basin." https://watershedmg.org/sites/default/files/documents/2020_fall_byob_zine_english_0.pdf.
DIY rainwater harvesting basin
Date:
Mar 12, 2025
Category:
Permaculture Tutorial
Tools:
Shovel
Why should you build a basin?
Lush vegetation that you can enjoy WITHOUT pulling from municipal water supply.
Harvest pristine water that is already falling onto your property, free of salts and full of micro-organisms that your plants will love.
Create an oasis for microorganisms, native flora and fauna, and you.
Mitigate flooding and all the headaches it brings.
Minimal maintenance for maximal return.
Rebuild the soil you live on.
Increase your property value $$$.
Recharge your regional aquifer.
Build a deeper connection between you and the patch of Earth you inhabit.
Respect for water.
Observe
Observe where the water naturally flows when it rains. Is it pooling in a spot you don’t want? Is it running off into the street? Is there water flowing in from a neighboring property? Where is the highest point on the property and where is the lowest point?
Tip: Use a map of the property (follow this tutorial), and draw out everything to organize your thoughts. Mark the direction that water is flowing on the site.
Where NOT to put a basin
Within 5 feet of your house (you don’t want water pooling at the foundation)
Above any underground lines, pipes, or cables (call your utility company locator at least three days before you plan on digging)
Above a septic drainage field or next to a drainage field if the water table is higher than 20’ (not common in arid environments)
In the middle of any major circulation paths (obviously)
Right next to the base of any established plants. As a general rule, dig at the edge of the existing plant canopy. You don’t want to harm the roots.
Mark the basin(s) boundary + overflow
Starting from the highest point on the property, mark the boundaries of the basin(s) and where they will overflow when full. In large rain events, the basins will fill up and you want to make sure you have a path for the water to overflow into another basin or off the property. The edge where the water overflows needs to be slightly lower. Don’t overthink it, you will have time to test and iterate as you observe how they function in rain events. Water moves from the highest point to the lowest point. Make your basins have rounded edges to reduce water erosion (water likes to make things round).
Dig!
Grab a shovel and dig down 6”-12”. The deeper it is, the more water it will carry. Try to make the base of the basin as level as possible. Make sure the overflow route edge is slightly lower to allow water to drain properly. To reduce erosion, where the edge of the overflow route loses soil, line the overflow route with rocks. Create gently sloped edges that are approximately 33 degrees.
Plant!
Take a hike! Observe what native plants are in your bioregion. Plants that prefer more drainage can go along the edge of the basin. Plants that prefer more water can be terraced along the edges (for deeper basins). Terraces can be stabilized with rock to reduce erosion. Grasses can go in the deepest part of the basin. If you don’t want to buy plants, you can buy a native seed mix and spread it along the edges of the basin before rain.
Mulch!
Do not skip this step! The goal is to create a sponge that absorbs rainwater and allows it to slowly sink into the soil. Local arborists will often deliver wood chips to your property for free. Wood chips are a great place to start. You can also use piles of leaves or tree branches as mulch. Mulch limits weeds and allows mycelium to proliferate which helps your plants be healthy.
Observe and iterate
Next time a big rain comes through, watch how the basins work. Where does the water go? Make corrections as needed.
DIY rainwater harvesting basin
Date:
Mar 12, 2025
Category:
Permaculture Tutorial
Tools:
Shovel
Why should you build a basin?
Lush vegetation that you can enjoy WITHOUT pulling from municipal water supply.
Harvest pristine water that is already falling onto your property, free of salts and full of micro-organisms that your plants will love.
Create an oasis for microorganisms, native flora and fauna, and you.
Mitigate flooding and all the headaches it brings.
Minimal maintenance for maximal return.
Rebuild the soil you live on.
Increase your property value $$$.
Recharge your regional aquifer.
Build a deeper connection between you and the patch of Earth you inhabit.
Respect for water.
Observe
Observe where the water naturally flows when it rains. Is it pooling in a spot you don’t want? Is it running off into the street? Is there water flowing in from a neighboring property? Where is the highest point on the property and where is the lowest point?
Tip: Use a map of the property (follow this tutorial), and draw out everything to organize your thoughts. Mark the direction that water is flowing on the site.
Where NOT to put a basin
Within 5 feet of your house (you don’t want water pooling at the foundation)
Above any underground lines, pipes, or cables (call your utility company locator at least three days before you plan on digging)
Above a septic drainage field or next to a drainage field if the water table is higher than 20’ (not common in arid environments)
In the middle of any major circulation paths (obviously)
Right next to the base of any established plants. As a general rule, dig at the edge of the existing plant canopy. You don’t want to harm the roots.
Mark the basin(s) boundary + overflow
Starting from the highest point on the property, mark the boundaries of the basin(s) and where they will overflow when full. In large rain events, the basins will fill up and you want to make sure you have a path for the water to overflow into another basin or off the property. The edge where the water overflows needs to be slightly lower. Don’t overthink it, you will have time to test and iterate as you observe how they function in rain events. Water moves from the highest point to the lowest point. Make your basins have rounded edges to reduce water erosion (water likes to make things round).
Dig!
Grab a shovel and dig down 6”-12”. The deeper it is, the more water it will carry. Try to make the base of the basin as level as possible. Make sure the overflow route edge is slightly lower to allow water to drain properly. To reduce erosion, where the edge of the overflow route loses soil, line the overflow route with rocks. Create gently sloped edges that are approximately 33 degrees.
Plant!
Take a hike! Observe what native plants are in your bioregion. Plants that prefer more drainage can go along the edge of the basin. Plants that prefer more water can be terraced along the edges (for deeper basins). Terraces can be stabilized with rock to reduce erosion. Grasses can go in the deepest part of the basin. If you don’t want to buy plants, you can buy a native seed mix and spread it along the edges of the basin before rain.
Mulch!
Do not skip this step! The goal is to create a sponge that absorbs rainwater and allows it to slowly sink into the soil. Local arborists will often deliver wood chips to your property for free. Wood chips are a great place to start. You can also use piles of leaves or tree branches as mulch. Mulch limits weeds and allows mycelium to proliferate which helps your plants be healthy.
Observe and iterate
Next time a big rain comes through, watch how the basins work. Where does the water go? Make corrections as needed.