How to properly drain travertine paver patio

[schnicks]

hi there, here's my situation:
· we're about to replace the old [water tight] flagstone patio between our house and pool with 16x24" travertine pavers [1.0" thick]
· all pavers will just 'butt' against the other; there will be no sealing grout, just locking sand;
· even so we're in dry southern california, i am not sure that the only drainage proposed by the contractor, a hard pipe SURFACE DRAIN SYSTEM with 4 or 5 drain covers to which the surface will 'fall' is sufficient;

since the paver joints allow water to flow into the paver-bedding and sub-base, wouldn't a 'french' drainage system [perforated pipes] be neccesary also? or i am i overly worried?

i just want to avoid any possible puddling of water, or worse settling of the bedding/sub-base and consequent buckling of our patio;
also, would there be possible water seepage through the foundation into the crawl space below our house, if not all water was removed by the surface drain system?

see included picture of the layout: travertine paver patio layout [NE view]

thanx all for your help.

m.