The solid particles may eventually clog the pipe.
Gutter drain pipe depth.
The trench should be at least 6 inches wide and slope down slightly 1 to 2 inches per length of pipe so water drains away from the downspouts.
Continue until you have completed the trench.
For the garage i used a downspout adapter without a leaf guard since there aren t trees close enough for that gutter to get clogged up.
The fastest way is to rent a trenching machine from a local tool rental.
To do this i cut the black corrugated pipe added a t and aimed the pipe upwards to the downspout.
It is most effective to place a drainage pipe in the ditch at a depth of 12 to 18 inches and then fill the ditch with gravel.
This trench would follow the natural contour of the ground.
If you have hard clay soil or rocky soil you can use an electric hand held demolition hammer tool to dig a trench.
If you live in a cold climate trapped water may freeze and burst the pipe.
I usually dig a trench about 12 to 14 inches deep for downspout drain lines.
Drain pipe slope maintaining a depth of 12 to 18 inches is best for drain pipes but the depth of the pipe may vary in order to maintain a downward slope which is critical for proper drain functioning.
Depending on the trench length and more important the type of soil digging the trench with a shovel can range from relatively easy to downright impossible.
Since my in ground pipe ran right past the garage i had the garage downspout dump in as well.