In the title compound C(13)H(27)N(2)O(3) (+)·Cl(-)·H(2)O, obtained by deprotecting the amino and carboxyl groups of an inter-mediate in the synthesis of the cyclic penta-peptide Galaxamide, a number of hydrogen-bonding inter-actions occur including aminium N-H⋯Cl, amide-carboxyl N-H⋯O, water O-H⋯Cl and carbox-yl-water O-H⋯O associations. The aminium N-H⋯Cl⋯H-N bridging extensions give rise to zigzag chains extending along the a axis, the overall two-dimensional structure lying in the (110) plane.