CASE STUDY 14 — Wolfe Airpark Expansion
18-Acre Airpark Expansion | Civil Engineering & Drainage Design

PROJECT OVERVIEW
JRH Engineering delivered complete civil engineering design for an 18-acre expansion of an existing airpark in Manvel, Texas. The project faced city opposition, a shallow storm sewer outfall, and tight budget constraints that made conventional permitting through the City of Manvel unworkable. JRH advised the client to pursue deannexation from the city — removing the city permitting barrier entirely — and engineered a dual-purpose runway ditch drainage system that met both aviation safety requirements and drainage district standards.

AT A GLANCE

Site Civil Design

● Full civil design for 18-acre airpark expansion including runway extension, grading, and drainage

● Existing runway ditches widened and deepened at a 1:12 slope — the specific slope required by aviation safety standards for aircraft operations

● Dual-purpose drainage channels created: runway safety ditches that simultaneously function as the site's detention system

● Lift station minimized the required pond footprint, preserving more land for airpark operations

Regulatory Strategy

● City of Manvel opposition identified as the primary permitting barrier within the project's budget

● Deannexation from the City of Manvel recommended and pursued — removing city jurisdiction and eliminating the city permitting track entirely

● County jurisdiction established, allowing the project to proceed through Brazoria County and CNR3 rather than city approval

Stormwater & Drainage

● Runway ditches designed to 1:12 aviation safety slope — dual-purpose as both aircraft safety feature and stormwater detention

● Lift station reduced pond footprint below what a gravity system would have required

● CNR3 drainage district approval secured concurrently with Brazoria County permitting

Permitting & Agency Coordination

● City of Manvel permitting track eliminated through deannexation — no city approvals required

● Brazoria County and CNR3 approvals pursued simultaneously after deannexation

● Aviation safety requirements (1:12 ditch slope) incorporated into drainage design — a single design element satisfying both FAA-standard safety criteria and drainage district requirements

THE CHALLENGE
City opposition and a constrained budget are a difficult combination. The City of Manvel was not going to approve the expansion on terms that worked financially — and the shallow outfall condition made conventional detention design more expensive than the project could support. Waiting for city alignment was not a viable strategy.

JRH's Approach
JRH identified the root problem: the city was the obstacle, not the engineering. The recommendation to pursue deannexation was a strategic call — remove the city from the equation entirely, establish county jurisdiction, and proceed on a timeline and cost structure that actually worked. Once jurisdiction shifted to Brazoria County and CNR3, the engineering solution became straightforward: widen existing runway ditches to a 1:12 aviation safety slope, creating drainage channels that served double duty as both required stormwater detention and aircraft safety features.

The Result
A fully permitted 18-acre airpark expansion — delivered after eliminating city opposition through deannexation and designing drainage infrastructure that satisfied both aviation and drainage district requirements simultaneously.

RESULTS

● City opposition eliminated through deannexation — permitting moved to Brazoria County and CNR3, where approval was achievable within budget

● Dual-purpose drainage channels designed to aviation safety standards — runway ditches serve as both aircraft safety features and stormwater detention

● Pond footprint minimized through lift station — more land preserved for airpark operations