Key Regulatory Updates Impacting Development in Houston
Recent updates at both the City of Houston and federal levels are changing how
development projects approach detention, permitting, and wetland impacts. These
changes offer new flexibility, reduced regulatory burden, and potential cost savings—
especially for smaller and redevelopment projects.
Houston Simplifies Detention with Chapter 9 Supplement
The City of Houston has adopted a supplement to Chapter 9 of the Infrastructure Design
Manual (IDM), delivering long-awaited relief for development and redevelopment projects.
What’s changed:
• Flat detention rate of 0.80 ac-ft/ac for projects under 20 acres
• Redevelopment credit of 0.40 ac-ft/ac for existing impervious cover
• De minimis exception allowing up to a 1% impervious increase for small
commercial improvements without triggering detention (one-time per property)
• Legacy projects protected under previously approved drainage criteria
• Clearer exemptions and jurisdiction-based guidance
Federal Update: New WOTUS Guidance
Following the Sackett v. EPA ruling, federal wetland regulations have narrowed.
Key impacts:
• Only wetlands with a direct surface connection to permanent waters are federally
regulated
• Isolated wetlands and ephemeral streams may no longer require Clean Water Act
permits
• Fewer federal permits, but potential for increased state and local oversight
Bottom Line
These updates reduce permitting barriers and improve feasibility for many projects, but
evolving local regulations make early coordination critical. Houston Civil helps clients
navigate these changes efficiently and strategically keeping projects moving forward.
