Higher sea levels, lower land levels and increased salt in irrigation water are some changes coming to Richmond because of climate change.
Looking at the 100-year forecast, Richmond city staff have suggested one solution could be raising land on agricultural properties to mitigate potential harm to farming viability.
But some on Richmond council balked at raising farmland, saying it could bring in other problems.
More than a year ago, council asked for a report reviewing the city’s Flood Protection Management Strategy with comments about raising land and how that relates to the viability of farmland.
The report by KWL Consulting Engineers entitled “Land Raising Review” cost $25,000 to commission.
John Irving, general manager of engineering and public works with the city, said the report was meant to support long-term flood protection.
He added there would be a lot of details needed on how to implement such a plan site by site of how and if land-raising solutions could be done.
“If you don’t do anything over the 100-year timeframe, likely a lot of agricultural viability will decrease with sea level rise as salinity increases and the ability to keep some of those properties dry decreases,” Irving said.
The report to council notes farmland in Richmond is “susceptible to saltwater intrusion” and this is expected to get worse as sea levels rise with climate change.
If the land is raised, the roots are higher and not affected by this saltwater intrusion. Furthermore, the report notes, it would allow for better drainage as there will be more unsaturated soil.
Since the city was diked, there hasn’t been any natural flooding, which used to bring in silt deposits.
Currently, land is subsiding by about two millimetres per year – without diking, it would have risen naturally and would be “slightly higher” than it is currently, according to the report to council.
Coun. Harold Steves raised concerns about changes in the salinity of the water in the north and south arms of the Fraser, noting some scientists say this is changing.
He also questioned where the soil would come from to raise the land, saying only local soil and soil from Delta are compatible with crops grown in Richmond.
Furthermore, he said if fill is put on top of Richmond soil, the land can no longer access groundwater.
In the end, council accepted the report for information with only Coun. Michael Wolfe opposing it.