Water has to leave a Spring site before anything else works, so developers here judge a contractor by how it handles drainage, detention and grading across large, flat tracts. We plan and supervise the earthwork, storm structures and pond excavation that move runoff off a pad and into a basin, and we keep the pad itself stable enough for the slab that follows.
The scale of the corporate campuses along Interstate 45 explains why. A January 15, 2015 report said the 385-acre ExxonMobil campus in Springwoods Village was due for completion by the end of that year, with about 3,600 of an expected 10,000 employees already at work. Another corner of the same development, CityPlace, covered 60 acres, with construction started in 2014 and room for up to 13 office buildings, two hotels and roughly a million square feet of retail. Land of that size cannot be graded building by building. It needs one drainage plan, built in a sensible order.
Under the slabs, moisture decides how the finished floors behave. Clay that stays damp near a basin and dries out under a parking field can move a floor in opposite directions, so we pair every grading plan with a subgrade moisture plan.
Drainage review and the permits behind a Spring pad
Harris County drainage criteria, detention sizing and outfall approvals usually come before the building permit, and reviewers want grades that agree from one sheet to the next. We check the civil drawings against the geotechnical report and ask the engineer to resolve conflicts before bidding, because a pond that is too shallow by half a foot changes every pad elevation upstream of it.
Any site larger than an acre needs a written stormwater pollution prevention plan. We install and maintain erosion control and SWPPP measures, keep inspection logs after rain and stabilize the entrance so haul trucks do not track mud onto public roads.
What changes project by project on large tracts
The Harris County Flood Control District's project C-118 shows how regional water planning reaches individual sites. It proposes a reservoir and flood control dam serving the Spring Creek watershed, with two candidate sites on Birch Creek and Walnut Creek in Waller County. Commissioners started it in December 2020 and a feasibility study led by the San Jacinto River Authority is under way.
A developer cannot design around a project that is not built, but can ask conservative questions about floodplain lines, pond volume and outfall capacity. We price drainage so those questions are answered in the earthwork quantities, and we carry a clear alternate for added pond depth so the owner can compare the cost of extra capacity with the risk of leaving it out. Commercial developers who phase a tract find that this keeps the first phase from boxing in the second.
Earthwork and drainage scope we coordinate
A typical package begins with clearing, topsoil stripping and mass grading to establish pad elevations and pond limits, then storm sewer, inlets, culverts and outfall structures, then fine grading to the tolerances the slab or paving needs.
We schedule trade partners for pond excavation, slope protection and concrete flumes. Setting culverts and headwalls before surrounding fill avoids digging out compacted ground later, and survey checks at each stage catch bust grades while they are inexpensive to fix. Inlets and manholes are set to line and grade before the surrounding base is placed, and we confirm that pipe slopes drain by gravity the way the engineer intended.
Offices, retail and flex space on prepared pads
The Hewlett Packard Enterprise headquarters, a campus that opened in April 2022, now sits in the same market as the ExxonMobil campus, which has about 9,000 employees along I-45 beside the community. Corporate users like these draw suppliers, hotels and service buildings, and each needs a graded pad with a plan for runoff.
We prepare sites for office buildings and retail centers, and we coordinate parking and drive-aisle subgrades so the pavement drains toward its inlets. Between campuses and shopping areas, work in The Woodlands and Conroe gives our trade partners a similar range of building pads to compare against.
Soil, moisture and the slab above it
Much of the subgrade here is clay that swells when it takes on water. Where the geotechnical report calls for it, we treat pad soil with lime or cement, or we place select fill over a moisture-conditioned base, and we compact in lifts at the specified moisture range.
Once the pad is ready, we protect it from ponding water and from heavy equipment that can pump the subgrade. A rain before the vapor barrier goes down means re-testing the surface, not covering it and hoping. We also set up curing plans for slabs that sit near ponds, because a floor that dries unevenly from one side will curl at the edges.
Sequencing earthwork before a wet season
Spring's flat ground drains slowly, so open earthwork is scheduled for dry months where possible. Ponds are cut first so that they can receive runoff, and temporary swales route water away from finished pads.
Where Interstate 45 provides the main haul route, we time loads for off-peak hours and keep material stockpiles near the work. Concrete follows grading by the shortest interval the weather allows, since a prepared pad left exposed through a storm usually needs rework before the forms go in. We also confirm batch plant capacity ahead of large pours so supply never sets the date.
Working beside ponds and busy corridors
Deep basins and steep slopes need guardrails, flagged limits and a competent person who checks them daily. Equipment operators work with spotters when trucks move near open excavations.
Along a busy arterial we separate truck entrances from public traffic with signs, flaggers and designated turn lanes, and we schedule the hardest manual work for the cooler part of the day. Every worker on a pond site is briefed on slopes, water depth and the location of ladders and rescue equipment, and supervisors stop work when lightning is near.
Plan your Spring drainage and pad work
Send the civil drawings, geotechnical report and your start date, and we will lay out pond, storm line, grading and pad work in order.
Common Questions
Why does drainage come before foundations on a large Spring tract?
Runoff has to reach detention before pads can stay dry, and the pond, storm lines and outfall control the finished grades for everything else. Building in that order avoids digging up completed pavement or filling low spots after the fact.
How do you judge whether clay subgrade needs treatment?
The geotechnical report gives plasticity and swell figures, and the engineer sets the treatment. We follow it, usually lime or cement treatment or a select fill cap, and confirm the result with compaction and moisture tests before the slab is formed.
Can detention ponds be built early to help with construction drainage?
Often yes. Cutting the pond early gives temporary runoff a place to go, and it supplies fill for pads. We coordinate sediment controls so the pond does not fill with silt before the final grade is cut.
What records do you hand over after earthwork and drainage?
Survey as-builts, compaction and density test results, pipe test records and inspection logs. Reviewers and lenders ask for them, and we collect them as the work progresses.