The Challenge

When Hurricane Sandy made landfall in 2012, New York City’s underground infrastructure was severely impacted. Treatment plants shut down. Underground utilities were flooded. Recovery extended for months.

In the aftermath, the Metropolitan Transit Authority sought cost-effective ways to prevent floodwater from entering access structures and underground vaults.

The objective was straightforward:

Protect existing infrastructure without rebuilding it.

Identifying the Gaps

Structure inserts were identified as a promising mitigation strategy. However, existing products did not meet the complexity of New York’s infrastructure.

Challenges included:

• Diverse frame shapes and sizes
• Protruding locking lugs
• Drop rings requiring tight tolerance
• Oversized 48-inch openings
• The need for gas monitoring without removing inserts

No single product addressed all conditions.

Engineering the Solution

Rainstopper worked with contractors including Zafra Minhas Construction and WBE Dorcas Inc. to develop five new insert designs:

• Stainless steel insert with extended lip and angled drop
• Square insert for ConEd electric utility structures
• Extended-life elastomeric gasket for long-term durability
• Large-diameter 48-inch insert
• Insert featuring an external gas detection port

All products passed third-party certified hydrostatic testing at 16 feet of water head. Units exceeded the 1,000-hour requirement, with some operating beyond 2,500 hours under sustained pressure.

More than 250 units were manufactured and installed following detailed on-site measurement training to ensure proper fit.

Results

• Standard specification approval with the MTA
• Installation across all five boroughs
• Floodwater prevention in parking lots, roadways, and utility structures
• Reduced inflow and infiltration into treatment systems
• No major infrastructure modification required

Ongoing Relevance

Flood protection systems must perform under pressure.
They must install efficiently.
They must work within existing infrastructure.

The inserts developed for the MTA remain in service and continue to support flood mitigation efforts across New York.

We didn’t approach this as a product exercise.
We approached it as a problem to solve.

Keep the water out.
Protect the infrastructure already in place.
Build solutions that work in the real world.

That’s how we approached New York then.
It’s how we approach flood mitigation today.

Questions about flood mitigation?

Phone: 318-667-4330
Email: Info@rainstoppercompany.com