Rock ramp design guidelines

Rock ramps or roughened channels consist of steep reaches stabilized by large immobile material (riprap). Primary objectives for rock ramps include:

• Create adequate head for diversion
  
• Maintain fish passage during low-flow conditions
  
• Maintain hydraulic conveyance during high-flow conditions
  

Secondary objectives for rock ramp design include:

• Emulate natural systems
  
• Minimize costs
  

The rock ramp consists of a low-flow channel designed to maintain biologically adequate depth and velocity conditions during periods of small discharges. The remainder of the ramp is designed to withstand and pass large flows with minimal structural damage. The following chapters outline a process for designing rock ramps.