Olmos Basin Stream Restoration

The FAA said we
can’t attract
wildlife. Now what
do we do? An urban
stream restoration
case study
Dr. Troy Dorman, P.E.
210.226.2922
Troy.Dorman@tetratech.com
K.M. (Milton) Rahman
210.207.5012
K.Rahman@sanantonio.gov
Bruce Cole 210.870.7204 cole@riverspecialists.com
Project Background
• City of San Antonio Airport Runway Extension begun
in 2005.
• Originally a traditional H&H Analysis with
CLOMR/LOMR submittal.
• Deferred 4 years for other projects
• New USACE 404 requirements in 2007 required
submittal of PCN or potential Individual Permit
• Partially Funded by FAA
• Floodplain permitting review by City of San Antonio
Airport Runway Site Pre-Project
Airport Runway Site Post-Project
StreamRestoration
Restorationisto
Rescue
Stream
thethe
Problem?
• Approximately 1,315 Linear Feet of
Jurisdictional Waters of the US.
• An on-site stream restoration approach with
a pool riffle sequence based on local curves
was developed to meet Corps desires to
achieve an equivalent functional value to the
current JWUS.
• During the course of the design, we were
notified that FAA regulations would preclude
the airport from building the mitigation in a
way that would attract wildlife.
The Discussion Went Like This
• Public client with set funding on a specific site.
• It just grew to two sites. Where do we mitigate for
the stream? There are no active mitigation banks
nearby.
• And we need to find a site for 450 trees.
• How about a public park? They are always looking for
trees!
• We are in the worst drought in 50 years! Irrigation is
the concern.
• The consultant should have this in their budget!
Mitigation Site Criteria
•
•
•
•
We need a degraded stream at least 1500 feet long!
We need room for 450 trees!
We need a source of irrigation water during drought?
We need someone to maintain the vegetation during the
first five years to comply with the permit.
• The mitigation area has to be permanently deeded by
legal instrument.
• We need it quick because the runway is already designed
and will go to construction soon.
• The FAA has to approve it since they are funding a
portion of the project.
Offsite Selection
A Public-Public-Public-Public-Private Partnership
• The FAA, USACE, City of San Antonio, San Antonio
River Authority and Alamo City Golf Trail.
– FAA – Wildlife Attractant Mitigation
– USACE – NWP 27 – Aquatic Habitat Restoration
– City of San Antonio – Expanded Runway, Floodplain
Administration and Tree Mitigation
– San Antonio River Authority – Stream Restoration and
Habitat Survey
– Alamo City Golf Trail – Golf Course Improvements
– Residents and Visitors – Beautification, Travel, Golf and
STREAM HEALTH.
The Olmos Basin Golf Course
The Olmos Basin Golf Course
Design Plans
Landscaping Plan
Stream Restoration Design
Bridge Removal and Relocation
City of San Antonio Permitting
Review Comments
• Floodplain Development Permits (FPDP)
Applicant Submits Plans
and Studies to Stormwater
Plan Review Team
SW Staff Reviews
Submittal
FPDP Approval by FPA
City of San Antonio Permitting
• Tree Permit:
– UDC Section 35-523
– 25% Preservation Required for areas
outside floodplain.
– 80 % preservation required if
located within Floodplain or
Environmentally sensitive area
– 100 % Preservation required for
heritage tree defined in UDC 35-523
– Mitigation: Protected trees that are
required to be preserved are to be
mitigated at the ratio described in
Table 523-2. ( Significant 1:1,
Heritage 3:1)
City of San Antonio Permitting
• Conditional Letter of Map Revisions (CLOMR)
CLOMR
Submittal
• Reports
• Electronic Models ( H&H)
Staff Performs
Review
• No Adverse Impact Policy
• Must Meet City’s Floodplain Ordinance (UDCAppendix F)
FPA Approval
• MT-2 Form signed by Floodplain Administrator
• FPDP issued to perform the associated work.