Hausman Road Drainage Project LC-9

Report
Collaborative Efforts Lead to Design
and Permitting Success:
Hausman Road LC-9
Andy A. Atlas, AICP, CP&Y
Wesley R. Young, PE, CFM, CP&Y
ASFPM
May 2012
Overview
•
•
•
•
Issues
Solutions
Process
New Tools
ASFPM
May 2012
Issues for Hausman Road Project LC9
• Three low water crossings over two
creeks:
– Flooding on Hausman Road
– Flooding of homes downstream
of Hausman Road
ASFPM
May 2012
More Issues for Hausman Road Project
• Roadway does not meet
current design standards
• Local, State, and Federal
Permitting required
ASFPM
May 2012
Initial Objectives
•
•
•
•
Improved Hausman Road with all weather access
Expand roadway to current design standards
Avoid/Minimize environmental impacts
Remove adjacent and downstream homes from the
floodplain
ASFPM
May 2012
Issues Complicating Objectives
• Engineering Design
– Bridge Height vs Channel Excavation
• Environmental Issues
– Section 404 Permitting
• IP vs NWP
– Tree Preservation
– Edwards Aquifer Recharge Zone
ASFPM
May 2012
Solutions
• Purchase property and convert to parkland
• Engineering
– Elevate road above Huesta Creek and its tributary
– Enhance channels to improve floodwater capacity
– Incorporate Natural Channel Design (NCD) elements
• Environmental
– Stream enhancement and mitigation
– Tree preservation
ASFPM
May 2012
Means / Procedure
• NWP 27 – Aquatic Habitat Restoration,
Establishment, and Enhancement Activities
• Stream Assessment provided baseline stream
health index
• Add elements to channel design to enhance aquatic
restoration
• Recalculate stream assessments for proposed
conditions
• Monitoring required as part of NWP
ASFPM
May 2012
Process
Preliminary
Engineering
Report
JUNE 2009
Tree
Preservation
Plan
JUNE 2010
Qualitative
Habitat
Evaluation Index
FEBRUARY 2010
Mitigation Plan
JUNE 2010
Enhancement
Goals
APRIL 2010
Alternatives
Analysis
MAY 2010
Nationwide Permit
27
Pre-Construction
Notification
OCTOBER 2010
ASFPM
May 2012
Preliminary Engineering Report (PER)
• Outlined existing conditions
• Summarized environmental
constraints including Waters of
the U.S., potential wetlands,
vegetation, and T&E species
habitat assessment
• Described 3 proposed
conditions options
ASFPM
May 2012
Qualitative Habitat Evaluation Index (QHEI)
• Biologist / Engineer team
assessed 15 transects across the
project site
• Evaluated various channel /
floodplain parameters
• Calculated scores for each
transect
• QHEI developed by Ohio EPA
ASFPM
May 2012
QHEI
Parameters to
Evaluate
• Substrate
• Instream Cover
• Channel
Morphology
• Bank Erosion
• Pool / Glide /
Riffle / Runs
• Gradient
ASFPM
May 2012
Enhancement Goals
• Provide unflooded access
along Hausman Road
• Address public safety and
flooding issues
• Enhance aquatic
resources, consistent with
NWP 27
• Return natural stream
function to previously
channelized stream
• Preserve and enhance
existing vegetation
• Ensure that the project is
financially feasible
ASFPM
May 2012
Enhancement Goals
Objective
Preserve heritage trees
Plant native trees (including understory) and grasses
Reestablish vegetation
Mulch and water preserved trees during construction
Preserve/enhance desirable environmental features
Shade pools/channel with tree canopy
Reduce erosion
Enhance water quality
Remove exotic plant species
Establish depressions for valley storage
Establish riffles and pools
Preserve and enhance canopy cover
Plant woody buffers along streets
Provide meandering low flow channel and increase channel sinuosity
CoSA
X
X
X
X
X
X
X
X
X
X
X
X
X
Augment the bedrock areas with additional size substrates
Add instream cover
Decrease the overall stream gradient throughout the project review area
QHEI
CP&Y /
Program
X
X
X
X
X
X
X
X
X
X
X
Construct small nesting islands and/or islands around heritage trees
Remove existing impervious cover
Re-create floodplain function with conveyance above the low flow channel
USACE
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Provide unflooded access along Hausman Road within the project limits
Maintain or increase area of riparian woodland
Provide flood protection for adjacent properties
Improve wildlife habitat
Manage stormwater runoff
Maximize project benefits while minimizing cost
X
X
X
X
X
ASFPM
X
X
X
X
X
May 2012
Enhancement Goals
• Used the data from the QHEI
• Identify achievable enhancement goals
• Restore natural stream characteristics
ASFPM
May 2012
Alternatives Analysis
• Evaluated 5 alternatives
• Identified impacts of each
alternative
• Analyzed enhancement
benefits of each alternative
ASFPM
May 2012
Alternatives Analysis
Hausman Road Alternatives Matrix
Review
Area
Excavation
Project
Total
Review
Project
Area of Area to
Review Area
Excavatio
be
(acres)
n (acres) Excavate
d (%)
TREES
Existing
Tree
Canopy
(acres)
FLOODPLAINS5
STREAMS
Area of
100-yr
Ultimate
Linear
Tree
Riparian Riparian
Maximum
Conditions
Tree
Existing Heritage Heritage Existing
Length of Feet of Streams Length of
Canopy to
Woodland Woodland
2-year
Stream Floodplain
Canopy Heritage Trees
Trees
Riparian
Existing Streams to to be Proposed
be
s to be
s to be
Stream Gradient4 Remaining
Remaining Trees2 Removed Preserve Woodland
Streams
be
Excavated Streams4
Removed
Removed Preserved
Velocity4 (ft/mi)
Outside
3
(%)
(#)
(#)
d (%)
s (acres)
(feet) Excavated
(%)
(feet)
(acres)
(acres)
(%)
(ft/s)
Project
(feet)
Review
Area
(acres)
Residential
Parcels with
Structures
some 100in 100-yr
yr Ultimate
Ultimate
Conditions
Conditions
Floodplain
Floodplain6
(#)
(#)
COST
Overtops
Opinion
Hausman
of
Road
Probable
within
Cost
Project
(millions)
Limits?
Alternative 1:
44.4
0.0
0
17.2
0.0
100%
39
0
100%
9.0
0.0
100%
3,813
0
0%
1,800
11.5
42
7.1
55
30
Yes
_
44.4
12.0
27%
17.2
6.8
61%
39
25
36%
9.0
6.0
33%
3,813
3,490
92%
1,800
8.2
33
2.7
26
9
No
$7.1
44.4
7.8
18%
17.2
4.7
73%
39
9
77%
9.0
3.9
57%
3,813
2,880
76%
1,800
8.2
33
6.0
44
22
No
$6.1
44.4
21.4
48%
17.2
7.4
57%
39
15
62%
9.0
4.2
53%
3,813
1,900
50%
2,100
5.2
28
2.7
27
9
No
$8.8
44.4
21.6
49%
17.2
7.7
55%
39
11
72%
9.0
4.1
54%
3,813
2,620
69%
2,100
5.2
28
2.7
28
9
No
$8.8
No Build
Alternative 21:
Channel Excavation to
Babcock Road
Alternative 31:
Channel Excavation to
Danvers Drive
Alternative 4:
Two Bridge Option
Alternative 5:
Three Bridge Option
Notes
1: The level of impact analysis for Alternatives 2 and 3 is not as detailed as the analysis for Alternatives 4 and 5 because Alternatives 4 and 5 are refinements of Alternative 2 and have been carried
to a higher level of design.
2: At the time of the heritage tree survey, right of entry was not available in the southwestern corner of the project review area. Therefore, some heritage trees may not
have been counted in this total.
3: Infringement of the root protection zone was considered
removal.
4: Based on the preliminary hydraulic
design.
5: The quantities in this section refer to the Huesta Creek floodplain and include areas adjacent to the project review area, south of Hausman Road
and west of Babcock Road.
6: The Alternatives matrix was conducted using 2009 Bexar County aerial photography, and as a result, newly constructed houses that have been built after the date the aerial photos were flown
have not been quantified.
ASFPM
May 2012
Recommended Alternative 5
• 3 Bridge Option with Channel Enhancements
–
–
–
–
–
Removes 21 residences from floodplain
Provides unflooded access
Provides extensive aquatic enhancements
Preserves over 70% of heritage trees
Preserves over 50% of riparian woodlands
ASFPM
May 2012
Tree Preservation Plan
• Coordinated with City Arborist
• Selection of plants had to meet
enhancement goals of USACE
• Plan coordinated for channel
design
– Planting density vs hydraulic
roughness
– Planting locations
ASFPM
May 2012
Mitigation Plan
•
•
•
•
Must address deficits identified in QHEI
Based on the enhancement goals
Must be verifiable and quantifiable
Must conform to USACE expectations for aquatic
enhancement
ASFPM
May 2012
Table 1: Objectives, Metrics, and Proposed
Actions/Results
Objective
Metric and Enhancement Goal Met
Proposed Action/Results
Preserve heritage trees
Calculate percentage of heritage trees preserved under
preferred alternative.
Enhancement goal met by objective: 5
A total of 72 heritage trees were identified in the project area. Project
engineers incorporated minimization and avoidance measures where possible
into the project design. Construction of the project would require the removal
of 15 heritage trees; however, as detailed in the Tree Preservation and
Planting Plan, these impacts would be mitigated with a total of 482 trees and
shrubs native to the San Antonio area.
Plant native trees and grasses
Calculate number of trees by species, canopy cover, and area
of native trees and grasses to be planted. Monitor species
survival rate for a period that will be finalized by CoSA and
the USACE.
Enhancement goal met by objective: 3, 5
A total of 482 native trees and shrubs would be planted in the project area.
Additionally, 21.2 acres of native grass seed would be planted. The survival
rates of these plantings would be monitored for a period agreed upon by the
USACE and CoSA. Please refer to the Tree Preservation and Planting Plan
in Attachment B for more details on species compositions and proposed
planting locations.
Reestablish vegetation
Calculate area of impervious cover converted to vegetation.
Monitor species survival rate for a period that will be finalized
by CoSA and the USACE.
Enhancement goal met by objective: 5
Approximately 3.9 acres of existing roadways and concrete slabs would be
removed from the project area. Native grass seed would be planted in these
areas (please refer to Attachment B for proposed planting plan). The survival
rates of these plantings would be monitored for a period agreed upon by the
USACE and CoSA.
Mulch preserved trees
during construction
Identify areas of preserved trees requiring mulching. Monitor
species survival rate for a period that will be finalized by
CoSA and the USACE.
Enhancement goal met by objective: 5
An orange mesh barrier fence would be placed around the root protection zone
(RPZ) of trees to be preserved. The areas inside the fencing would be mulched
to reduce moisture stress. The survival rates of these plantings would be
monitored for a period agreed upon by the USACE and CoSA.
Preserve/
enhance desirable
environmental
features
Identify rare/native vegetation and habitats. Calculate areas
by habitat type. Calculate percentage of these areas
preserved by preferred alternative.
Enhancement goal met by objective: 3, 4, 5
An area containing a mix of native grasses and herbaceous species was
identified south of Hausman Road, between Huesta Creek Channel Two and
Huesta Creek Tributary A. Roughly 90 percent of this area would be preserved
with approximately 17 native tree plantings along the eastern edge.
ASFPM
May 2012
Table 2: Summary of Existing Conditions
vs. Proposed Improvements
Objective
Existing Conditions
Proposed Actions
Preserve heritage trees and
preserve/enhance desirable
environmental features
72 heritage trees in project review area
57 heritage trees to be preserved;
164 potential heritage trees (canopy value of
875 ft2 or more) to be planted;
21.2 acres of native grass and wildflowers to be
planted. Would preserve existing area
containing a mix of native grasses and
herbaceous species.
Remove exotic plant species and plant
native trees and grasses
Numerous exotic and/or invasive species
67 mature (DBH ≥ 6 inches) invasive/exotic
trees removed; 482 native trees planted
Preserve and enhance canopy cover
16.3 acres of canopy cover in project
area
12.2 acres would be preserved;
5.3 acres to be added
Improve wildlife habitat
Channelized creek, impervious cover, and
numerous invasive species compromise
value of wildlife habitat
Plant 482 native trees and 21.2 acres of native
grasses and wildflowers that provide food and
shelter to wildlife
Establish depressions
No depressions are present
20 aquatic depressions totaling 21,600 sq ft
(0.5 acres) proposed
Establish riffles and pools
No riffles or pools present
22 check dams/riffles to be placed within the
three proposed watercourses
Provide meandering low flow channel
and increase channel sinuosity
Existing sinuosity rating: none to
moderate
Proposed sinuosity rating: moderate to high
ASFPM
May 2012
NWP 27 PCN
• Adapted NWP 14 application form to NWP 27 as
per USACE recommendation
• Form simplifies the process
• Incorporated Mitigation Plan and previous
documents as appendices
• NWP 27 approved without comment
ASFPM
May 2012
Keys to Success
• Clearly defined goals
• Collaborative approach between and within
agencies, program, and consultant team
• Communication (monthly progress meetings with
program and team progress meetings)
ASFPM
May 2012
Results / Benefits
By coordinating the engineering design with permitting
requirements:
• Sustainable design
• Buy-in from all stakeholders
• NWP 27 approved without comment
• Significant time savings
• Cost Savings
• Remove downstream homes from the floodplain
• Stream restoration/enhancement
ASFPM
May 2012
Current Assessment Tools - TXRAM
• QHEI replaced by TXRAM
• Texas Rapid Assessment Method
• Aquatic Resource Compensation Calculator
ASFPM
May 2012
Thank You’s
•
•
•
•
•
Bexar County Flood Control Program
City of San Antonio Storm Water Engineering
USACE Fort Worth District
AECOM
Terra Design Group
ASFPM
May 2012
Questions?
ASFPM
May 2012

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