Gutter_self-cleaning design

In the permaculture design manual, Chapter 7 - Water.
there's a brilliant diagram of gutters (see the circled one in the attached pic.)

Does this gutter design actually exist?
IF so, where can it be purchased?
Any experience with it?

There is a design very similar to this on the market called leafguard. The concept is the same in the drawing you shared, with water's surface tension and adhesion clinging to a curved surface as it wraps around into the gutter with the leaves and other debris going over the top and not into the gutter. It's a great idea, but the reality is it only works with very light rainfall. If it starts raining hard or really coming down, the rainwater shoots right over the top along with the leaves. Leafguard often has a display at home shows and such, with the design working nicely. Ask the representative to increase the water flow to mimic heavier rainfall, and if they actually do it, water ends up on the floor. I have yet to see a design like this function as intended with water flow rates of a downpour thunderstorm, like 2.5 inches of rain in an hour. That sounds like a lot, but storms like this are a common occurrence nowadays for me here in middle tennessee. The amount of rain coming off an average size roof is astonishing. For example, a 2 inch/hour heavy thunderstorm on a 1000 square feet of roof area will have about 1240 gallons of water enter a gutter. (here's how I got that number: 1000 square feet x 144 inches in a square foot = 144,000 square inches. 144,000 divided by 231 (there's 231 cubic inches of water in one gallon) = 623 x 2 (for the 2 inches of rain) = 1240 approximate gallons.

Jason Vath wrote:In the permaculture design manual, Chapter 7 - Water.
there's a brilliant diagram of gutters (see the circled one in the attached pic.)

Does this gutter design actually exist?
IF so, where can it be purchased?
Any experience with it?

There are variations on the top left design.  We have something called a leaf eater that has worked well for us. http://rainharvesting.com/product/leaf-eater-original/  They do need to cleared out periodically and I still get leaves in my gutters.  There are other similar options but it seems to me that the bigger your gutters and the more fall you have the better.

Our home is three years old, and we live in the west coast of Vancouver Island, (also known as the "WET Coast").  We endeavored to install a leaf free system, as we have a lot of fir trees around that love to clog gutters.  We went with formed on site, professionally installed, large gutters, and purchased a perforated metal plank system that goes under the shingles but on top of the gutter...helpful but not to the extent I expected.  Biggest problem, crud coming off the asphalt shingles (the granules) and significant needle incursion.  

In my opinion, the biggest issue is lack of sufficiently steep slope in the gutter...but in hindsight, I would have eliminated the downspout and gone for chains or the basket dispersal method shown on the top left.

I suspect the circled design would not perform on a steep roof, or in heavy rainfall.  

Jason Vath wrote:

Does this gutter design actually exist?
IF so, where can it be purchased?
Any experience with it?

Here's at least one version of it:  https://www.youtube.com/watch?v=qigEby268pA

https://www.leafguard.com/about-us

Jason Vath wrote:In the permaculture design manual, Chapter 7 - Water.
there's a brilliant diagram of gutters (see the circled one in the attached pic.)

Does this gutter design actually exist?
IF so, where can it be purchased?
Any experience with it?

Cleaning the gutters on my house was quite an adventure. I had to climb up a ladder and scoop out all the leaves and dirt that had collected in there. It was a bit dirty and sometimes a little scary being up high, but it was important to keep the water flowing smoothly. After I finished, I felt good knowing that my house was protected from water damage. It's not the most fun job, but it's necessary to do it once in a while to keep everything working well.

Look at this product comparison

And another comparison

I am going to have to take a closer look at my gutters.   I have what I thought was standard gutter screening on mine and they never clog up.  I might have installed something not so standard.  That was 20 years ago, so my memory is a little fuzzy.

I'm less enamored with gutters every year

They seem useful for rainwater harvesting, but not much else

Cleaning the gutters on the second-story roof is a hazardous or expensive maintenance chore.  There are many designs for "leaf guards" that only work under certain conditions

Clogged gutters are worse than no gutters, concentrating water flow in the overflow spill location

As far as diverting rainfall from basements, even here in the rainy northeast, it seems the most important consideration is siting and grading of the lot

If the house is situated properly so bulk rainwater moves away from the foundation, no gutters are needed.  There are 300 year old houses in my town with no gutters

If the house is situated in a low spot where water drains, the basement will have water issues, with or without gutters

The gutters only intercept the rainfall over the footprint of the house, maybe 1,000 square feet or so.  But the watershed surrounding your house is many times larger and of course water can wick sideways as well as vertically