diff --git a/data/processing/projection.py b/data/processing/projection.py
index a172385..746862f 100644
--- a/data/processing/projection.py
+++ b/data/processing/projection.py
@@ -98,7 +98,7 @@ z[flt_x] = interpolate.griddata(
     (x[flt_x] - x[z_crossing] + bathy_hires[hires_crossing, 0]),
 )
 
-np.savetxt(out_root.joinpath("bathy.dat"), z, newline=" ")
+np.savetxt(out_root.joinpath("bathy.dat"), z[::-1], newline=" ")
 np.savetxt(out_root.joinpath("hstru.dat"), np.zeros(z.shape), newline=" ")
 np.savetxt(out_root.joinpath("poro.dat"), np.zeros(z.shape), newline=" ")
 np.savetxt(out_root.joinpath("psize.dat"), np.zeros(z.shape), newline=" ")