square cylinder - problem plotting!

Hi guys,

Im sure this is a simple problem but i cannot work out how to do it! I have a simulation for a dam break flow with a downstream square obstacle in the centre of the 200 x 200 channel set up with the bounce back boundary conditions below.
I want to produce a contour plot with the square obstacle filled in using the matlab function ‘fill’ but i am not sure how to combine a command to fill the area and produce the contour plot at the same time? Any help would be very helpful! Thanks!

% Square cylinder obstacle conditions
% left edge of square
f1(90:110,90)=F3(90:110,90);
f8(90:110,90)=F6(90:110,90);
f5(90:110,90)=F7(90:110,90);
% right edge of square
f3(90:110,110)=F1(90:110,110);
f6(90:110,110)=F8(90:110,110);
f7(90:110,110)=F5(90:110,110);
% bottom edge of square
f4(90,90:110)=F2(90,90:110);
f7(90,90:110)=F5(90,90:110);
f8(90,90:110)=F6(90,90:110);
% top edge of square
f2(110,90:110)=F4(110,90:110);
f5(110,90:110)=F7(110,90:110);
f6(110,90:110)=F8(110,90:110);