Oct. 29--A few small puddles of water remained on the concrete floor of the basement when Rosalind Billingsly moved into a one-story house on Rothwell Heights Lane in Olivette in 1997. She said she thought they were remnants of a last-minute cleanup by the previous tenant.

But Billingsly learned with the first heavy rain that the puddles were not a good sign. Sewage backed up through the drain in her basement, submerging clothes, bicycles and her children's toys.

"Even light rains would cause the water to back up into the basement," Billingsly said.

Through 2008, Billingsly's basement flooded more than twice a year on average. The floods resulted in 21 claims for damaged property and $36,000 in payments from Metropolitan St. Louis Sewer District. (Two claims were filed for the property before Billingsly moved in.)

In the last decade, her neighbors on Rothwell Heights filed dozens of claims and received more than $100,000 in payments from MSD.

Systemwide in the last 10 years, MSD has paid out $31 million on more than 10,000 claims for property damaged because of blocked mains and an overtaxed system.

Nearly a third of the claims were in connection with one event -- the remnants of Hurricane Ike last year. MSD customers filed more than 3,000 claims, and the district paid more than $3.4 million in damages related to that flooding.

While considered an emergency situation, the storm highlighted some of the maintenance problems MSD has been having with its aging sewer system.

Since its formation in 1954, MSD has taken in more than 79 different sanitation districts in St. Louis County and city, and is responsible for more than 9,600 miles of sewer lines. About 800 miles of sewer lines are more than 80 years old, which is problematic considering MSD estimates the average life of a sewer to be 75 to 100 years, said MSD Executive Director Jeff Theerman.

MSD is responsible only for sewage or rainwater that backs up through its pipes into someone's home. If water flows through a door or a seam in a foundation into a basement, MSD is not liable because it is considered overland flooding and more along the lines of an act of God than a symptom of a malfunctioning storm system.

For the last decade, problems with the system have manifested themselves in the increasing number of claims MSD customers filed for damaged property.

The district paid out $21.5 million from 2004 to 2008, more than triple the $6.1 million paid out on claims the previous five years.

CLAY PIPES AN ISSUE

Many of the claims were for blocked mains and originated in St. Louis city and the inner ring of St.