Award-Winning Corrugated Steel Pipe Rehabilitation Restores Vital Irrigation Line in Isleta Pueblo

By: Contech Engineered Solutions

A Collapse Below NM47 Leads to an Award-Winning Fix

Named the NCSPA Rehabilitation Project of the Year, this emergency repair project in Isleta Pueblo, New Mexico, showcased the resilience and reliability of modern corrugated steel pipe rehabilitation. In October 2023, a 42-inch riveted metal pipe—originally installed in 1978—collapsed beneath New Mexico State Road 47. This deep-bury irrigation line, 20 feet underground, delivered critical water resources to farmland on the west side of the Rio Grande.

The failure put a vital corridor at risk. The pipe ran directly under the main entrance to the Isleta Pueblo Reservation, meaning road closure was off the table. The Middle Rio Grande Conservancy District (MRGCD) needed a fast, trenchless solution that would restore flow without disrupting access.

Trenchless Technology Paves the Way

After exploring alternatives, MRGCD opted for a tunnel boring machine (TBM) to install a 50-inch steel casing without disturbing the surface above. This trenchless approach preserved road access while laying the groundwork for a full corrugated steel pipe rehabilitation. Inside the new casing, the team slip-lined a 42-inch polymer-coated spiral rib pipe—an efficient and long-lasting replacement.

This method allowed MRGCD to bypass traditional excavation, minimize construction impacts, and bring the pipeline back online in record time.

Why Corrugated Steel Pipe Was the Ideal Choice

The rehabilitation effort centered around a polymer-coated spiral rib liner system manufactured by Contech Engineered Solutions. It delivered on all fronts:

Efficient Hydraulics
The pipe’s smooth interior produced a Manning’s “n” of 0.012—ideal for high-demand irrigation systems.

Durable and Strong
Its boxed exterior ribs provided the structural strength to handle deep cover and groundwater pressure.

Corrosion Resistance
Site-specific soil testing indicated moderate corrosivity. The polymer coating added a protective barrier, extending the expected service life far beyond conventional options.

Altogether, these features made this corrugated steel pipe rehabilitation both cost-effective and future-proof.

Two Days to Restore Flow

After dewatering the site, crews used a 120,000-pound excavator to slipline the 18-foot pipe segments into place. The process took just two days. Lightweight cellular grout filled the space between the liner and casing, securing the system and preventing future settlement.

At both ends, about 50 feet of additional 42-inch pipe was installed using open-cut methods, complete with 45-degree bends to tie into existing earthen channels and function as a siphon.

A Reliable Water Supply for Generations

This award-winning project ensured the Isleta Pueblo community could continue relying on the Rio Grande’s water for agriculture—without compromising access or facing long-term maintenance issues. Through innovation, trenchless technology, and high-performance materials, MRGCD turned a crisis into a model example of corrugated steel pipe rehabilitation.