The Rains Are Coming—Are Your Street-side Basin Inlets & Roof Gutters Ready or Clogged?
By Brad Lancaster
Like much of the country, we are in a record drought with high temperatures drying us out even more; stressing many shade plants, and threatening our cooling soil-carbon sponges—so we should be doing all we can to capture and hold on to cooling, life-enhancing moisture.
But even as the summer rains have begun in my home of Tucson, Arizona; many people who have installed passive street-runoff harvesting earthworks and/or roof-runoff-harvesting gutters and tanks are NOT ready to receive that free water because their basin inlets and roof gutters are clogged!
Are YOU ready or clogged?
Street-side tree basin inlets

Photo: Brad Lancaster

Blue arrow denotes water flow.
Note: ideally this basin would be larger to capture more water, but this is way better than no basin.
Photo: Brad Lancaster

The concrete curb is stained darker from the dirt that was removed to prepare the basin to receive the coming rains—there is now at least a 2-inch (50-mm) drop from the bottom of the street-curb core hole (or in another case could be a curb cut) to the top of the soil (or mulch) in the basin.
This way, the flow of the in-coming water will speed up, NOT slow down. So, sediment carried by the in-coming water will flow through, instead of settling out and clogging the inlet.
Blue arrows denote water flow.
Photo: Brad Lancaster

Street gutter water flow is from left to right.
Photo: Brad Lancaster
More important points:
- Water flows downhill, so make sure the elevation of the entire bottom of your street-side basin (and the surface of any mulch within it) is well-below the street gutter and inlet elevation. The deeper the basin the more water you can collect.
- See here for important elevation and slope relationships within street-side basins, and tips on how you can expand their capacity.
- Observe your street-side basin inlets during and after rains, and throughout the rainy season. Clean as necessary.


Blue arrows denote water flow.
Photo: Brad Lancaster
Roofs & their gutters
Around the world among rainwater-harvesting cultures, people clean their water catchments before the rain. Children often have this responsibility, sweeping a flat roof- or patio-catchment. At my home, the responsibility is mine.
I have to do this at the beginning of every rainy season because my roof and street gutters fill up with abundant pollen, pods, and leaves from overhanging trees (all of which makes for great soil-building and water-conserving mulch when relocated to the soil’s surface).
If you don’t clean your gutters, you’ll likely lose a lot of water you could’ve otherwise captured.

Photo taken at the beginning of the rainy season before gutters were cleaned.
If there is debris on the roof too, then clean the roof first, then clean your gutters.
Photo: Brad Lancaster
To help keep the debris collecting in your roof gutters from getting into your rainwater tank install a rainhead downspout inlet screen (and clean your gutters at the beginning of the rainy seasons).
For more
See the new, full-color, revised editions of Brad’s award-winning books
– available a deep discount, direct from Brad:

Volume 1
Essential reading!
See its eight guiding principles for the harvest of all waters, and an additional ten guiding principles specific to active systems harvesting rainwater in tanks.
Includes simple calculations enabling you to effectively size your systems for maximum performance.

Volume 2
Lots of info on how to create street stormwater-harvesting basins/rain gardens, curb cuts, curb cores and a whole lot more!
Includes simple calculations for ideal sizing of your water-harvesting earthworks, and to estimate their cost of implementation.