Major gravel extraction in South Canterbury's Opihi River has been described as a "win-win" for everyone involved.
About 30,000cu m of gravel in the Opihi riverbed, just north of Pleasant Point, is being removed to improve flood paths, and is providing a major source of material for contractors.
Environment Canterbury's consent monitoring team leader Roger Gould said it was critical to remove gravel built up since the 1986 floods, which formed a large island in the river.
Flood water could then spread evenly, lessening the chance of it bursting the flood banks and threatening Pleasant Point.
ECan senior engineering officer Bruce Scarlett said if construction company Fulton Hogan did not carry out the work, ECan would have had to pay to have it done.
"It's a win-win situation - the contractors get the gravel they need for their businesses, and we get the required work done.
"It's not hit and miss - they are even given specific levels that the riverbed must be left at when they finish.
"We have kept in mind the recreational, environmental and aesthetic values of the river when considering what can and can't be done," he said.
Companies must apply for consents to take the shingle, and there were usually two to three major shingle extraction projects going on in South Canterbury's riverbeds at any time, as well as a handful of smaller consents.
