The fact you are asking the question indicates you see the potential problem. You do not need a chorus of other voices to confirm what you already see as a problem. If there is no ability to redirect water to an even lower location you can begin to understand why this lot may or should be priced lower in equivalent units.
Below grade properties require constant vigilance in maintainence and awareness of what is taking place above you. A significant increase in impervious surfaces above can be bad news for those in low-lying areas.
I suppose you've already got the answer you need by now. But, it's always a good idea to see the evidence the builder has that this location is not going to pose water problems. They will have test results of the soil and so forth.
Failing that, if the deal is really good, you could always invest in having your own tests done if the builder will allow it. That way, you've got results independent of what the builder is providing.
Let us know how this turned out for you!!
Coldwell Banker Burnet
licensed MN Broker
It sounds like you do have some valid concerns, but if you are just looking for advice before you pick a specific lot with a builder in this area, I would ALWAYS recommend that you hire a buyer's agent to represent you in that purchase, rather than just working directly with the builder. Keep in mind that the services of a professional buyer's agent do not actually cost you anything. Builder reps will try to convince you that they are giving you a "special deal" or a "discount" if you work directly with them, but our statistics show that an unrepresented buyer of new construction will usually end up with a much worse deal than the ones that have a buyer's agent represent them in that same development. ( and I only use the word "usually" because I could never provide the legal proof that it's more common than that)
Now, I am not soliciting you to use ME, but please find a buyer's rep that you feel is skilled and reputable, and then go out and make a great deal happen.