There’s no simple way to segregate the broad and narrow views of hydraulic purity.

Wolf Creek flows into Slippery Rock Creek. Thorn Run and Breakneck Creeks flow into the Connoquenessing — all tributaries of the Beaver River, which empties into the Ohio, then the Mississippi. All are connected, like capillaries leading to the aorta, carrying and sustaining life and vigor.

It’s not so roundabout to realize that what goes down the drain in Renfrew or Prospect might end up in the mouths of a tiger shrimp and scallops in the Gulf of Mexico, some of which find the way to our own plates and palates. It’s all one big watershed from the Alleghenies to the Rockies, after all.

So, what is the level of our responsibility for the stewardship of this ecosystem? Must the rain that falls on Butler County exit our land as clean as it arrived? Is it the purest drop in that literal ocean? Does it need to be?

Some people are asking this question today in Evans City. The state Department of Environmental Protection has ordered the borough to design a stormwater management plan that reduces both sediment and phosphorus by 10 percent in the Breakneck and Connoquenessing creeks. The borough has until early September to come up with the plan. If the plan is accepted, DEP will issue a five-year stormwater permit in March. The borough will have until 2023 to reduce the sediments and phosphorus by 10 percent.

The frustration, expressed by council President Lee Dyer, is that the state imposes this mandate on stormwater action without providing any money to enact it. Dyer says the borough must pay $18,000 just to get the plan off the ground. It will cost more than that to actually reduce the sediment.

It’s also frustrating to consider that just upstream and downstream, other municipalities continue with rapid residential, commercial and industrial development, bound by different sets of regulations and timetables to implement them.

How will the sacrifice of neighboring municipalities measure up to the sacrifice that Evans City is being asked to make?

Maybe that’s the wrong question. Maybe the right question goes something like this:

Does your grandchild have an expectation 20 or 40 years from now to bite into a native shrimp or scallop harvested from the Gulf of Mexico? If the answer is yes, then we all have to solidify the way we think about protecting our water drainage system.