Problem $7.$ You are flowing water from the side of a canal into a large, rectilinear gravel pack

$(K=5\frac{m}{?}$ day$)$ with a height of $2\mathrm{.}1$ m $($assume that this is the total head at the sand pack$/$canal

contact$)$ in order to filter it$.$ To deliver the water, we need $2$ m of head after running through the

filter. Water must remain in the sand pack for an average of $6$ hours to be 'filtered'. Assume that

the sand has a porosity of $0\mathrm{.}29.$ Find the thickness of the sand pack, assuming that the effective

height of water across the sand pack is $2\mathrm{.}05$ m $.$ Hint. You will manipulate the seepage velocity

and specific discharge equations. Answer in meters.