Catch Basin Performance

[KokoAkita]

That catch basin should have been installed at the low point or the area should have been graded so that water will naturally drain into it. The fact that the water running off from the roof and not falling into the catch basin directly is irrelevant . Do you have perforated, solid, or pvc pipe running from that catch basin? Where is it draining to? What is that downspout draining into? A splash block or another catch basin?