Gravel, Fill and Topsoil Delivery in Mobile, AL

Made ground on a low site

The USDA soil survey maps the ZIP's center point as Urban land-anthroportic udorthents complex, 0 to 8 percent slopes, industrial. Paved or built-over ground makes up 50 percent of that map unit. Anthroportic udorthents are soils made of material that people hauled in and spread, such as dredged sand, construction fill and rubble.^[1]

The Smithton series makes up 5 percent of the same map unit, and the top mineral layer at that point is a fine sandy loam. Made ground like this varies a lot over short distances. One test hole may hit clean sand while the next one turns up clay, shell or broken concrete.^[1]

The soil is rated poorly drained and falls in hydrologic soil group B/D. It behaves like group D, with very slow infiltration, while the water table is high, and like group B where it has been drained. After a heavy rain, low areas can hold water for a long time.^[1]

Shrink-swell in the top 100 cm is low, at 1.2 percent, so swelling is not the worry. Soft, wet subgrade is. The ground at the center point stands 10 feet above sea level.^[1],[2]

Gulf rain, a brief winter and raising the ground

The NOAA normals station at Mobile DWTN AP, AL, about 5 miles away, averages 60.5 inches of precipitation a year. Summer thunderstorms and tropical systems can drop a great deal of rain in one event. On low, poorly drained ground, that water needs a planned path off every surface.^[3]

The downtown airport station logs 15 days a year with a low of 32 F or colder. Light freezes do little to a well drained base. A base that sits in water is another story, since even a short freeze can loosen the surface stone.^[3]

The median last spring freeze there falls on February 21. The median first fall freeze arrives on December 6. Planting season starts early and runs late, with only a short break in the coldest weeks.^[3]

Storms that arrive when the water table is already high leave nowhere for the rain to go. Raising work surfaces and building swales that lead to a storm drain or a ditch are the two most reliable fixes on this kind of ground.^[1],[3]

Raising low ground is step one on a wet site, and the choice of fill matters. Fill Dirt carries more clay and silt, so it compacts into a firm, stable mass that holds its shape under a slab, a shed or a raised parking area. It drains slowly, which is fine under a paved or stone surface that sheds water.^[1]

Fill Sand drains freely and compacts well when damp. It is the better choice under pavers, around pipes and anywhere water must pass through. On its own, it can shift at the edges, so it needs a firm border or a compacted cover.^[1]

Whichever you choose, spread it in thin layers and compact each one, and slope the finished surface toward a drain or a swale. Cap areas you plan to plant with a few inches of Topsoil.^[1],[2]

A hard-wearing yard or lot surface

Work yards, equipment lots and loading areas need a surface that handles heavy wheels on soft ground. Start by stripping soft material, then lay a heavy woven geotextile so the stone does not sink into wet subgrade.^[1]

The state's highway department builds the layer under its pavements to its rules for Crushed Aggregate Base, found in Section 825 of the Standard Specifications for Highway Construction (2026).^[4]

For a private lot, a thick lower layer of #4 Crushed Stone or Railroad Ballast spreads heavy loads and lets water drain through. Over that, compact Road Base or Crushed Concrete to fill the voids and make a firm surface. Asphalt Millings make a durable top layer that binds as it warms and keeps dust down.^[1]

Edge the lot with a ditch or a Drain Rock trench, and slope the surface toward it. Riprap at outfalls and culvert ends stops the flow from cutting into the ground during heavy rain.^[1],[3]

Patios at homes near a high water table need a little extra height. Build the base of Road Base a few inches above the yard, screed Concrete Sand, set the pavers, and sweep Stone Dust Screenings into the joints. A border of Pea Gravel or River Rock around the edge takes the runoff.^[1]

Planting in made ground

Hauled-in fill rarely makes good garden soil. Raised beds filled with Garden Soil give plants a clean, rich root zone above the wet, mixed material below. For trees, dig a wide planting hole and backfill with native soil mixed with Compost.^[1]

Beds on poorly drained ground do best when raised even a little. Mulch with Brown Shredded Mulch or Red Mulch to hold the soil in place during storms and keep weeds down. Refresh it once or twice a year, since heat and rain break it down fast.^[1],[3]

With the median last freeze in late February, many plants can go in early. Keep frost cloth handy for tender plants during the short cold spells that can follow.^[3]

A fresh layer of mulch before the median first freeze in early December protects roots during the few cold nights of winter.^[3]

Railroad Ballast, Riprap and other heavy stone

Industrial and commercial sites on soft, made ground call for larger stone than most homes do. Railroad Ballast is coarse, angular stone that interlocks into a stable layer under heavy loads and leaves plenty of space for water to drain. It works as the lower course of an equipment yard, a construction entrance or a laydown area.^[1]

Riprap is larger still and armors ditches, banks and outfalls where fast water would cut into fill. Set it over fabric, with the biggest pieces at the point where the flow hits hardest. On a low site with heavy rain, Riprap at each culvert and drain outlet prevents most of the washouts that would otherwise need repair after a storm.^[1],[3]

For a construction entrance, a pad of Railroad Ballast or #4 Crushed Stone at the gate knocks mud off tires before trucks reach the street. Top it up as it fills with soil, since a clogged pad stops doing its job.^[1]

Homes in 36602 and in Mobile

The Census counts 892 housing units in ZIP 36602. Detached single-family houses make up 14 percent of them.^[5]

The median home in ZIP 36602 was built in 1974. Owners occupy 25 percent of the occupied homes.^[5]

Mobile as a whole holds 98,380 housing units. Detached houses make up 67 percent of that total.^[5]

The citywide median build year is 1975.^[5]