I could fixed this by using -1 for SRID in the view. It also works by using GeomFromEWKT and setting the correct SRID. Here is the fix https://github.com/3nids/qWat/commit/772bc48b6a98ab7b1228ad18e9537015634cd384 But still, is there a smarter way of interpolating a curve over multipoint and returning a linestring?