The lake was located in a tectonic depression without natural drainage.
The hitherto natural drainage was no longer possible at this depth, so that water had to be pumped out with hand pumps.
As the water had no natural drainage, it was calculated that probably 1000 million tons would have to be raised by mechanical means.
This lack of natural drainage makes places within the city vulnerable to landslides during the rainy season.
The majority of the outdoor area on the site is covered with water permeable pavers for natural drainage.
Bad natural drainage and heavy rain created this pond.
Seven other rivers and six creeks serve as natural drainage for the city.
The philosophy now, as he put it, is to let the landscape and natural drainage determine where development should occur.
The southern part of the county has better natural drainage, and this area was first cleared for agriculture.
Glaciers to the north blocked the natural northward drainage of the areas.