League warns sewer-backup coverage depends on negligence; no-fault option exists but may not be cost-effective

Council members asked the League about sewer-backup claims and whether the city can be held liable when basements flood.

Matt Becker said the League's policy "provides coverage for sewer backups if if you're found negligent." He described Wisconsin case law as providing strong protections for municipalities under the discretionary-immunity doctrine: unless a ministerial duty (a clearly defined, non-discretionary obligation) is breached — for example, a specific written policy to clean a sewer that is ignored — the city generally is not liable.

Becker said the League offers a "no-fault sewer" product that removes liability determinations and provides coverage without the negligence inquiry. However, he said the math typically does not work out for a city Oshkosh's size because of the frequency of sewer-backup claims; Becker recommended most municipalities avoid the no-fault product for budget reasons.

As practical advice to residents, Becker recommended citizens consider adding sewer-backup coverage to their homeowner policies; he said many standard homeowner policies do not include backup coverage unless specifically requested and that typical supplemental limits run in the $5,000–$25,000 range.

Becker also described common causes of sewer backups — improper items flushed, vandalism, tree roots, construction strikes and pipe deterioration — and said the League can provide public information to residents. He said he has already supplied materials to "Paul" (unnamed in the transcript) for citizen outreach.

The council did not take formal action during the briefing; staff will review Becker's materials and include them in public-information efforts if appropriate.