Work to address erosion and flood risk in Southshore and South New Brighton has been approved by the Christchurch City Council.
In Southshore, that that included replacing or covering structures along the estuary edge to reduce the erosion risk and constructing a new bund near the current one.
In South New Brighton a new bund would be built between the jetty near Beatty St and the southern end of the campground in Halsey St, and the estuary edge would be restored with a cobble beach.
Council staff said some of this work would reduce the flooding risk to 450 homes as well as a nearby campground.
The estimated cost to do this was $12.5m.