Landslides resulted from specific preventable builder choices, not natural accidents

Evidence

The list of potential problems was quite long. Some soils and geologic formations were naturally unstable. Builders could destabilize a hillside by steepening the slope, by increasing the height, by adding too much weight at the top, by undercutting the base, or by removing natural supports from the bedding planes. Blasting might set material moving. When builders created terraces by cutting and filling, the fill had to be sufficiently compact to bear the load: If the fill included too much vegetation or trash, if the fill was not layered properly, or if the fill retained water because the subdrainage system was inadequate, then the terrace might collapse. Water was a grave threat. When wet, clay soils could turn into slippery gels. The sheer weight and pressure of a saturated slope could cause the ground to move. Below the surface, water even could act as a lubricant, allowing bedrock to slip and slide. — Adam Rome, The Bulldozer in the Countryside, 678

Categorization

• XREF: connects to: Courts held developers liable for landslides, rejecting acts-of-God defenses — Adam Rome, The Bulldozer in the Countryside:…, 677; Builders’ site design decisions, not roof and pavement area alone, drive suburban flooding. — Adam Rome, The Bulldozer in the Countryside:…, 805; Suburban sprawl created flood damage faster than engineered protections could counter — Adam Rome, The Bulldozer in the Countryside:…, 698

Broader Connections

• Builders’ site design decisions, not roof and pavement area alone, drive suburban flooding. #complicates (0.72) — Adam Rome, The Bulldozer in the Countryside, 805
• Suburban sprawl created flood damage faster than engineered protections could counter #qualifies (0.70) — Adam Rome, The Bulldozer in the Countryside, 698