Storms on Friday evening continued into Saturday at the Losail circuit, and while no rain fell in the evening the track did not dry sufficiently for riders to venture out.
Rivers continued to flow across the track surface, while standing water in the run-off areas also caused concern - despite efforts to clear it.
Capirossi estimated 80% of the track was completely dry, saying:
The main problem of the track was there is no drainage, because we don't expect rain in Qatar. We discovered this especially during the [pre-season] Moto2 and Moto3 test, and today in these conditions. In the run-off area at Turn 8, there was nearly a lake. The problem is, without drainage, the water coming up from the bottom. We tried to take away the water with a pump but, when we thought it was good, after 10 minutes it came out again. This is why we tried to keep [delaying the schedule], but we never resolved the problem. Now the situation is a little bit better, but even now the track is not ready.
Capirossi highlighted "the braking area of Turn 1, a little bit Turn 3, braking for Turn 4 and Turn 10" as the areas worst hit.
A large body of water also rested on the start-finish straight, when an additional - but ultimately cancelled - session to help riders evaluate the conditions was due to start.
Capirossi said work would continue overnight to try to dry the track for Sunday evening's race, even though there is an outside chance of more rain, with further developments planned before MotoGP returns in 2018.
"The thing we want to do tonight to improve the drainage is put a pump inside to try to take off all water, in case tomorrow we have rain again," he said.
"We can continue all night, and we can continue tomorrow morning because there was nothing more we could do.
"For sure we're thinking to do some work for next season, but here now the situation is like that."
Capirossi admitted the drainage problems had only really been "discovered" with this weekend's rain, but said it would have proven problematic with a day or night schedule.
The 2009 Qatar night race was postponed by rain, and riders are not convinced about the prospect of lapping the circuit with floodlights reflecting off a wet surface, despite Capirossi reporting he felt it was fine earlier this year.
"I think with the experience of today, day or night, it's impossible to race in the rain," he said.
"Without drainage it's no different in the day or night. It's not just because we are in Qatar, when we were at Sepang or Jerez or Misano, any track is the same.
"When we have a lot of water we have to cancel."
Read the original article on Eurosport: MotoGP qualifying cancelled in Qatar, poor drainage blamed