We have recently been stressing to our logging contractor force the importance of

properly installing roads and stream crossings to protect water quality. The effort seems to be

working. One of our contractors $$ Clearwater Logging $$ recently brought a troublesome

stream crossing in the Piedmont to us to get our advice about how to handle it$.$ The

schematic is attached. He has the following questions:

$$ At the P$.$I. labeled as $$X$,$ he wants to install a $75-$foot radius curve. The distance from the

P$.$I. to the boundary of the streamside management zone is $65$ feet. Does he have enough

room to install this curve? How did you determine this?

$$ The area upstream that drains past this crossing covers $20$ acres. He would like to use a

single pipe on a permanent road. The local supplier has $24,30,$ and $36$ pipe in stock. What

size pipe do you recommend, and why?

$$ At the P$.$I. labeled as $$Y$,$ you want your external to be at least $15$ to avoid a soft spot of

ground that is unsuitable for a road. What curve radius should be used to achieve this if the

P$.$I. is $70$ feet from the SMZ boundary and you want to make sure a log truck can get around?

Please perform the necessary calculations to answer these questions. Attach your

calculations to a one$-$page memo that explains your findings and upload it to Canvas by