Sluggish sewers, smelly backups and insurance squabbles have led 13 local residents to file lawsuits against the City of Spearfish, claiming its negligence led to tens of thousands of dollars in damages to their homes. Stretching back to 2008, some residences near Eighth and Hudson streets have sustained a series of backups, as recently as last October, that have flooded basements with raw sewage and stormwater, leaving in its wake stinking messes, lost possessions and frustrated homeowners.