Reducing Runoff From Your Own Property

Water quality in Mobile Bay is decided mostly on land, and mostly by an accumulation of small decisions on individual properties. This is the list of those decisions.

None of it is dramatic. All of it works.

Understand what your property does

Walk it during a heavy rain. Genuinely — put on a coat and watch where the water goes.

You will find that most of it moves across hard surfaces quickly and leaves the property at one or two points. That concentrated flow is the problem: fast water carries sediment, and it doesn't soak in anywhere.

The goal for everything below is the same. Slow it down, spread it out, let it soak in.

Downspouts

The single easiest change. Most downspouts discharge onto a driveway or a paved path, which sends roof water straight to the street.

Redirect them onto planted ground, at least a few feet from the foundation. Water that lands on vegetated soil infiltrates instead of running.

If the ground is compacted, a small gravel-filled basin at the outlet gives it somewhere to sit while it soaks.

Rain barrels

Simple, cheap, and they capture the first flush of a storm — which is the dirtiest portion, carrying whatever accumulated on the roof since the last rain.

A single barrel doesn't hold a large storm. It holds enough to matter for the frequent small ones, which is most of them.

Reduce hard surface where you can

Permeable options for paths and parking: gravel, permeable pavers, stepping stones with planting between. Water passes through instead of running off.

Break up long runs. A driveway draining continuously to the street moves more water faster than the same area interrupted by a planted strip.

Rain gardens

A shallow depression planted with species that tolerate both saturation and drought, positioned to receive runoff from a roof or driveway.

It holds water briefly, lets it infiltrate, and the plants take up nutrients. Well suited to this climate and considerably better looking than a drain.

Site it at least ten feet from a foundation, in a spot that already collects water.

Fertiliser

Use less, or none. Nitrogen and phosphorus reaching the bay feed algal blooms; the blooms die and decompose; decomposition consumes oxygen. That process is directly connected to hypoxic bottom water in this bay.

If you fertilise, apply at less than label rate, never before rain, and never on hard surfaces. Granules on a driveway are going to the bay entirely.

Native plants don't need it, which is the simplest fix available.

Keep a buffer

If you have frontage on a creek, ditch or the bay itself, an unmown vegetated strip along the water does more per square foot than anything else you can do.

Roots hold the bank, vegetation traps sediment, and the strip intercepts what the rest of the property sends toward the water. Ten feet is meaningfully better than nothing; thirty is much better than ten.

Mowing to the water's edge is the single most common and most consequential mistake on residential waterfront.

The small habits

Sweep, don't hose. Whatever you rinse off a hard surface goes downstream.

Pick up after pets. Bacterial contamination from pet waste is a documented and substantial source in developed watersheds.

Wash the car on grass, or at a facility that treats its water.

Check the septic system if you have one. Failing systems are a continuous discharge and owners frequently don't know.

Keep leaves out of the street. In a gutter they are a nutrient source; on your beds they are mulch and insect habitat.

Why it adds up

No single property caused water quality problems in this bay. They are the aggregate of thousands of individual decisions made without much thought about where the water goes.

That is discouraging as a diagnosis and encouraging as a prescription, because the same arithmetic runs in reverse.