function v = watervol(h)
% watervol calculates the volume of water in the tower.
% Input argument
%   h   Water level in meters
% Output argument
%   v   Water volume in cubic meters
% Written by Alan Usas, 12/23/08

if h<=19
    v = pi*12.5^2*h;
else
    rh = 12.5 + 10.5*(h-19)/14;
    v = pi*12.5^2*19 + pi*(h-19)*(12.5^2 + 12.5*rh + rh^2)/3;
end