The Hydraulics Model Annex (HMA), built in 1982, houses IIHR’s Mechanical Shop. Shop personnel construct the physical models used in much of IIHR’s research and maintain all other research-related facilities. A Sediment Laboratory, three research flumes, office space for mechanical shop personnel, and Fluids Teaching Laboratory equipment are also located here.

However, the majority of the space remains available for a constantly changing array of short-term small- and medium-sized hydraulic models for both applied and fundamental research projects. These models are continuously being built, utilized, and torn down here.

Specialized laboratories and equipment:

• Sediment Laboratory
• Mechanical Shop (includes a welding facility, carpentry shop, EA Machine Shop and EA carpentry area)
• Tilting flume (high-gradient sediment flume)
• Kennedy flume (low-gradient sediment flume with integrated wind tunnel)
• Two-foot flume (fixed-gradient flume with low turbulence characteristics
• 125,000-gallon underground sump