It’s often easy to forget how big changes come about because of small things done on a personal level.

Take for example, the topic of last week’s column about the attempt to change the way we think about rainwater. I referred to the Greater New Orleans Urban Water Plan, which looks at ways to hold water instead of whooshing it out of the way as quickly as possible.

The plan proposes a number of large projects designed to hold water. Holding water helps the underlying layers of soil and prevents subsidence — a major problem in this area. But big projects by themselves are not part of the total solution.

And that’s where the small things come in.

If you have gutters on your home, it’s likely that the downspouts lead to some kind of concrete pathway — even if it’s just your driveway or a sidewalk — to direct that water out to the street where it eventually will wind up in the drainage system.

But it actually makes more sense if those downspouts are aimed at the green portions of your front or back yard. That doesn’t get the water to the drainage system, but then, that’s the point. If the water soaks into the ground, it lessens the chances of soil layers drying out. It’s the drying out that eventually leads to subsidence and sinkage.

Then there’s the issue of concrete. Big cities have too much of it. Even bedroom communities are covered in concrete as more homes go up, more roadways are constructed and more commercial properties with large paved lots are built.

Concrete is an issue at the homeowner level as well. The more pavement you have on your property in the form of driveways and paved front yards, the greater your contribution to the problem.

Last week, Dana Eness, executive director of The Urban Conservancy, talked about the problem of too much concrete at a forum sponsored by The Lens, a New Orleans news website.

Paving large parts of front yards to create parking spaces is a problem that feeds upon itself, she said. If someone puts in a driveway because on-street parking in their neighborhood is a problem, they’ve actually worsened the situation.

A new driveway takes an on-street spot away because no one can park in front of the curb cut. Then, someone else on that block may want to put in a driveway too as their own solution to the parking problem. You can see how things just pile up from there.

It’s logical that actions at the homeowner level can aggravate or alleviate such big problems as rainwater runoff. After all, the root of the word “ecology,” which studies the relationship between living things and their environments, comes from the Greek word for “house.”

The New Orleans Sewerage and Water Board is trying to educate people at the citizen level with its Green Infrastructure program. It includes instructions on how to use rain gardens and rain barrels and how to disconnect downspouts.

There also is a “water literacy” program, called Ripple Effect, for local students, and a number of other similar projects.

It’s good that agencies like S&WB are working on solutions. Sometimes it’s easier for governments to continue to push development with an eye on the increased tax revenue that will come from it.

But a short-term gain can often lead to a long-term loss, and today we’re paying the price for some bad planning.

Homeowners, too, have to look at the long view, and the small changes they make literally in their own back yards can pay off in the long run.

Dennis Persica’s email address is dpersica@theadvocate.com.