Connecting Garden Drainage

Hello to All askaboutmoney members,

I am starting to do my homework and gather some information regarding "installing a garden drainage system". (some great guides on this site). I am going to "attempt" to do the work myself (with help from two of my good mates, who dont know yet) I have a idea how to install the drainage system.

However, I have two "black plastic" manholes outside my kitchen window. I persume one is for waste and the other is for water?

My question is, when I install the garden drainage can I connect the perforated plastic pipe to the house water system, will that be a problem?

Thanks for your help,
James.