Capacity - Capacity

[barnes]

Hello, I am designing a drainage system to collect water from 4 downspouts on the back of a house (back is about 40 feet and whole house is about 1250 square feet). The back of house lies 60 feet from a creek where I can install a downfall. I can also stop short of the creek and design a land drain with gravel and perforated pipe above a lawn area. My question is would a land drain of 12in x 12in about 15 feet long (max depth 24 in) have sufficient capacity using rigid 4 inch or 3 inch PVC and eliminate the need to trench to the creek? The soils is hard clay and avg rainfall is about 12 inches a year for during winter only (California, USA). Any suggestions on best practices or other issues?
Thank You

[lutonlagerlout]

hard to say without looking but surely it wouldn't be that hard to trench a 4" pipe to the creek?
landrains dont always work too well in clay
LLL

[barnes]

hey lutonlagerlout,

thanks a ton for the reply. i am not a contractor. i just enjoy learning about things and enjoy the fruits of hard work and of course saving some money in the process. that said i was on the fence, my gut said just go to the creek....my lack of knowledge asked if this was not best practices and not necessary. (clay soil....how much can a land drain hold..etc ). that said you helped put the issue to rest and i will be digging this weekend with no doubts.

thanks friend.

[seanandruby]

Maybe your 4" downpipes could branch in to a 150 carrier pipe to the creek, or have them going into a catchpit with a 150 out.