Stormwater Management & Drainage
Welcome
Hello, and welcome. This is Super Structures General Contractors — a national general contractor headquartered in Powhatan, Virginia — here to help you and your clients build something that lasts. We're glad you're with us, and we look forward to connecting with you.
Buckle up: Stormwater Management & Drainage is one of those skills the pros never skip. Here's the big idea to walk away with: Design stormwater early; ponds eat both land and budget. Learn it well and it's one more tool nobody can ever take from you.
Development adds impervious surface (roofs, pavement), which creates more and faster runoff. Regulations require you to manage that water so you don't flood neighbors or pollute streams.
What's required
- Detention/retention — ponds or underground vaults that hold back runoff and release it slowly, so peak flow after development isn't worse than before.
- Water quality treatment — removing pollutants (sediment, oils) before discharge, often via ponds, bioretention, or filters.
- Conveyance — storm pipes, inlets, swales, and outfalls that move water safely off-site.
Why it dominates civil design
Stormwater often consumes a big chunk of the site (ponds take land) and budget. Designing it efficiently — and early — protects both your yield and your pro forma.
Going Deeper (Intermediate)
Stormwater must be managed: collect runoff and control both quantity (so you don't flood downstream) and quality (so you don't pollute). Systems are designed to handle specified design storms.
Advanced / Pro-Level
The engineering and the land it consumes:
- Detention (hold and release at the pre-development rate) vs. retention (hold and infiltrate).
- Design storms (10/25/100-yr), conveyance (inlets, pipes, swales, channels), and hydrology modeling.
- Water-quality BMPs / LID (bioswales, basins) per NPDES MS4 rules.
- Floodplain work triggers FEMA review (no-rise, LOMR).
- Downstream impacts must be analyzed. Stormwater basins can eat real developable acreage and cost — a factor in the yield study, not an afterthought.
Practice Challenge
Why can stormwater requirements reduce the number of lots a site yields? (Answer: detention/retention basins and water-quality BMPs take up land — that acreage can't hold lots — so stormwater directly lowers yield (and adds cost); it must be in the yield study and pro forma, since "developable" land minus drainage isn't the gross acreage.)
In Practice
Stormwater detention gets added late and eats a fifth of the buildable site — yield the developer never planned for. Design stormwater early.
Common Mistakes to Avoid
- Designing stormwater too late
- Underestimating the land ponds consume
- Ignoring water-quality requirements
Takeaway: Design stormwater early; ponds eat both land and budget.
Educational content — not legal, engineering, or financial advice. Requirements vary by jurisdiction; always confirm with the local authority and your professional team.