Breakwater

"Ah, I believe I have just the thing for you!" says Duplicitous Dan, pulling a fine piece of crafstmanship from the shelf behind him.  "This is a perfect copy of the one rumored to belong to Odysseus.  If I recall correctly, you and Skinny were examining it yesterday."

"That must be what I'm looking for then," you  reply.  As you pay for the item, a sheet of paper flutters out of it.  You bend down to pick up the note from Skinny.

"Now bring this item to the infrastructure for ___________ of the city."  Growing accustomed to the pattern, you flip it over to see the next puzzle.

-The flow rate through any pipe, in gal/min, is an integer.

-There are two sizes of copper pipe. The smaller of the two has a cross-sectional area of one square inch. The larger has a cross-sectional area of five square inches.

-There are three sizes of steel pipe, with cross-sectional areas of two, three, and four square inches. They are completely indistinguishable from the outside.

- You should assume that the density and heat capacity of water do not change with temperature.

- You should also assume that there is no heat loss to the atmosphere through the walls of the pipes or tanks, i.e. temperature changes occur ONLY via mixing.

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