Fracture network generated by KRACK (Carl Renshaw) assuming various flaw density and growth.  Top: flaw density = 0.0004, a = 0.5; Middle: flaw density = 0.0002, a = 0.5; Bottom: flaw density = 0.0002, a = 2.   Right: Networks with non-conducting fracture removed.  All networks have a spatial density = 1.2