Gravel, Stone, Sand and Soil Delivery in Lewisville, TX

Low clay ground that can flood

The USDA soil survey maps Seagoville clay, occasionally flooded, at the center point of ZIP 75057, and the Seagoville series makes up 100 percent of that map unit. The words occasionally flooded are part of the unit name, and they mean the survey expects floodwater to cover that kind of ground now and then. Any surface built near that point should be planned for the day water rises across it.^[1]

The top mineral layer is clay. The survey rates it moderately well drained and places it in hydrologic group D, with very slow infiltration and high runoff. Its shrink-swell rating for the top 100 cm is high, at 7.5 percent. Wet clay like this swells and gets sticky, then shrinks and cracks as it dries. Stone laid on top of it without fabric slowly sinks into the clay and disappears.^[1]

Clay that has just been flooded or soaked should be left alone until it firms up. Driving equipment or wheelbarrows across it while it is wet smears and compacts it into a slick, airless layer that drains even worse than before. A few dry days make the work faster and the result much better.^[1]

The flood note in the map unit name is worth reading before you dig. A shed slab, a raised bed or a gravel pad set in a low corner may sit in water after a big storm, while the same structure a few steps uphill stays dry. Watch where water gathers during the next heavy rain and mark those spots. Build hard surfaces on the higher ground and let the low corners become planted areas or drainage features.^[1]

Old river terraces underneath

The USGS state geologic map shows Terrace deposits at the center point, made of sand, clay and gravel, and of Pleistocene age. River terraces are old floodplain surfaces left behind as a river cut down through its valley. Layers of sand and gravel can sit within the clay at different depths, so a deep dig on one lot can turn up very different material than one nearby.^[2]

The ground at the center point lies 470 feet above sea level. That height describes one point and does not tell you how a lot drains. Small differences in grade across a yard matter far more, and on low clay ground a few inches of height can decide whether a patio stays dry after a storm.^[3]

Storm rain and mild winters

The NOAA normals station at Grapevine Dam, TX, about 8 miles away, averages 38.9 inches of precipitation a year, with 0.1 inches of snow. Heavy spring and fall storms do most of the damage, dropping a lot of rain on clay that cannot absorb it quickly. Runoff then collects in low spots and along fences, and any loose material in its path moves with it.^[4]

The station counts 44 days a year with a low of 32 F or colder. Its median last spring freeze is March 14 and its median first fall freeze is November 17. Freezes are short, so frost does less harm than the swing between soaked and dry clay. Plan surfaces that drain fast and stay firm when the ground is wet.^[4]

Parking and paths that stay above the water

Extra parking and walkways are frequent jobs on apartment and townhome grounds. On flood-prone clay, raise the finished surface slightly above the surrounding grade. Strip topsoil, lay a strong woven fabric over the clay, then build the base with Road Base or Crushed Concrete compacted in layers. The fabric is not optional here, since without it the clay will swallow the stone within a season or two.^[1]

Top the base with Driveway Gravel or 3/4" Crushed Stone, or with Asphalt Millings for a darker, firmer finish that packs down well. Give the surface a slope toward a planted area or the street, and add a trench of Drain Rock along the low side. On group D clay, that trench may be the only place runoff can go during a heavy storm.^[1],[4]

For paths between buildings, compacted Decomposed Granite or Stone Dust Screenings over a Road Base layer gives a firm, even surface that sheds water. Keep paths slightly higher than the lawn beside them. If water still crosses a path after storms, a short culvert or a band of River Rock under the path lets it pass without washing out the surface.^[1]

Beds and drainage on heavy clay

Plants set straight into wet clay can drown. Raised beds filled with Garden Soil, or a blend of Topsoil and Compost, lift roots above water that collects after storms. Mix Compost into the clay beneath each bed over time to loosen it. Plant tender annuals after the March 14 median last freeze, and finish beds with Black Shredded Mulch or Brown Shredded Mulch.^[1],[4]

On low clay ground, a dry creek bed is worth the space it takes. Dig a shallow, winding channel from the wettest spot toward the lowest outlet, lay fabric and line it with River Rock, with larger Riprap at bends and at the outlet. Between storms it looks like a landscape feature. During heavy rain it carries water away from walks and buildings.^[1]

Mulch on low clay ground has to stay where you put it. Floodwater and fast runoff can lift loose chips and float them across a lawn or into a drain. Shredded mulch knits into a mat that holds better, and a raised edge of stone or steel around each bed adds a lip that keeps it in. Where a bed sits right in a water path, River Rock or #57 Crushed Stone makes a cover that will not wash away.^[1],[4]

Housing in ZIP 75057 and the Texas base spec

The Census counts 7,361 housing units in ZIP 75057. Lewisville as a whole has 54,237. Detached single-family houses make up 35 percent of homes in the ZIP, below the 46 percent share citywide. Owners occupy 36 percent of the occupied homes in the ZIP. Homes in the ZIP have a median build year of 1995, and the city's is 1997. Apartments and shared grounds account for a large part of the housing, and their landscape crews order mulch, path stone and drainage rock often.^[5]

Item 247 in the Texas Department of Transportation Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges (2024) covers Flexible Base, the compacted stone course that state road builders place beneath pavement. Home and property projects carry much lighter loads, but the same idea of a firm, well-graded layer over prepared ground holds.^[6]