LACKLAND CORRIDOR GATEWAY

LACKLAND CORRIDOR GATEWAY

DISTRICT 4 COUNCILMAN: REY SALDA?A

PROJECT MANAGER: ALMA NUNEZ

PRESENTER: TROY DORMAN, PhD, P.E., CFM

TETRA TECH

ECOSYSTEM SERVICES:

This project affords the opportunity to enhance the ecosystem services of our urban environment. Ecosystem services are the processes by which the environment produces resources that offset our everyday lives. The goal of the site development is to restore or supplement four categories of ecosystem services: provisioning (production of food/water); regulating (climate control/ disease control); supporting (nutrient cycles/crop pollination); and cultural (spiritual/recreational benefits).

ABSTRACT:

The Lackland Corridor Gateway Monument project is centered on a sculpture honoring the Air Force basic training mission at Lackland AFB in San Antonio, Texas. The site, partially owned by TxDOT and partially by the Joint Base

San Antonio (Air Force), will be transformed into a park setting by a City of San Antonio capital improvements project. Evaluating the Results for Existing Conditions

The transformation starts with removing 900 ft. of existing poor functioning concrete stormwater drainage channel and lifting it to a higher functioning ecological state through stream restoration. The restoration will reduce stream velocity and reconnect the stream to its floodplain to reduce downstream flooding. Runoff from all new onsite parking areas will be managed through a bioretention area sized to capture the 90th percentile storm and then slowly released into the stream to provide high quality base flow. Two additional bioretention areas will capture the 90th percentile storm from adjacent roadways that drain through the site reducing pollutant loads, erosion, and mitigating the peak flow effects from impervious cover. The integration of native and site appropriate vegetation including riparian, upland, and

SITE

BIORETENTION BASIN SECTION

Urban Riparian Reforestation:

Concerned with the rapid development of its region, the City of San Antonio engaged American Forests to complete an urban systems analysis (updated May 2009). The report quantified the impact of the changing land cover for the mitigation of storm water runoff, air and water pollution, and the provision of carbon storage and sequestration. The anticipated quantified value to the ecosystem services through the new native riparian and upland tree plantings on this +5-acre site prorated in context of the May 2009 updated American Forests Canopy Analysis equates to: ?2.06 acres of tree canopy. ?Management of 27,872 cubic feet of storm water; estimated value of $17,860 annually. ?Removal of 364 pounds of air pollutants; estimated value of $865 annually.

grassland species improves viability of the site and reduces water usage. The proposed tree canopy includes 161

native trees, carefully selected vegetation and also a butterfly habitat for the endangered Monarch Butterfly. The site

will include interpretive signage to inform visitors of the LID features and their benefits to human habitat. The project is

currently in final negotiation with the contractor and will complete construction within 6 months. The City of San Antonio

Parks department will assume maintenance of the project after the contractors 1 year warranty period ends. The San

EXISTING FLOOD PLAIN 3D MODEL

Antonio River Authority, who selected the project for a competitive $100,000 LID grant, will also verify performance Lackland AFB Corridor Gateway

7

and viability of the BMPs for up to two years after construction is completed.

MASTER PLAN:

The vision of District 4 City Councilman Rey Salda?a is to recognize the value of Joint Base San Antonio-Lackland as part of the history and future of San Antonio as Military City USA. The design intentions of the streetscape enhancement conceptual master plan are two-fold:

ELEV. 745

3' THICK BIORETENTION MEDIA

1

C-26.0

2 - 6" DIA. PVC SOLID

STA:0+56.44 ELEV:737.00

1

C-26.0

740

ELEV. 745 735

EXISTING

GRADE

STA:0+10.54

ELEV:737.030' THICK

BIORETENTION MEDIA

1 PROPOSED C-26.0SIDEW2A-L6K" DIA.

PVC SOLID

STA:0+56.44 ELEV:737.00

EXISTING

1:1 SLOPE

740 730

735 725

0+00 730

725

0+00

GRADE

STA:0+10.54

STA:0+21.8E4LEV:737.00

ELEV:731.42

4" UNDERDRAIN

30 MIL PVC LINER STA:0+21.84

ELEV:731.42

STA:0+36.36 ELEV:731.42

4" UNDERDRAIN

30 MIL PVC LINER

STA:0+36.36 ELEV:731.42

PROPOSED

SIDE2WALK

C-26.0

STA:0+62.93 ELEV:731.42

01+:510SLOPE

4" SOLID PIPE

2

C-26.0

STA:0+62.93 ELEV:731.42

0+50 4" SOLID PIPE

1

C-26.0

3' THICK BIORETENTION MEDIA

ELEV. 745

3

12" OVERFLOW

3' THICK

C-27.0

740

BIORETENTION MEDIA

ELEV.

745 735

12" OV3E0RMFILLOPWVC 3

LINER

C-27.0730 740

1:1 SLOPE

36" RECLAIMED

W73A5TER LINE 725

STA:0+71.40 ELEV:731.42

30 MIL LINER

0PV+C90

1:1 SLOPE

730 36" RECLAIMED

WATER LINE

725

STA:0+71.40 ELEV:731.42

0+90

LID

Strategies Master NOTE: BIORETENTION AREAS MAY NOT BE EXCAVATED UNTIL BIORETENTION MATERIALS HAVE BEEN APPROVED. CONSTRUCT EACH BIONROETTEE:NBTIOIORNEATRENEATIOWNITAHRINEASMMAAXYIMNUOMT BE 2-WEEXECKAVTIAMTEEDPEURNIOTIDL.BIORETENTION MATERIALS HAVE BEEN APPROVED. CONSTRUCT EACH BIORETENTION AREA WITHIN A MAXIMUM 2-WEEK TIME PERIOD.

Plan

CHEngineering - Planning - Transportation - Related Services 415 EMBASSY OAKS - SUITE 205 San Antonio, TX. 78216 OFFICE: (210) 341-6200 FAX: (210) 341-6300 CH FIRM NUMBER: F-8478 Engineering - Planning - Transportation - Related Services 415 EMBASSY OAKS - SUITE 205 San Antonio, TX. 78216 OFFICE: (210) 341-6200 FAX: (210) 341-6300 FIRM NUMBER: F-8478

I I

TBPE Firm No. F-3924 700 N. Saint Mary's Suite 300 San Antonio, TX 78205 210.299.7905

Date:

TBPE Firm No. F-3924 700 N. Saint Mary's Suite 300 San Antonio, TX 78205 210.299.7905

Revisions/Submissions

Date: Revisions/Submissions

78283-3966

FAX (210) 207-2197

PEDESTRIAN VIEW FROM SW MILITARY HWY

DOUBLE DROP CROSS VEIN DETAIL 1

EXISTING CONCRETE CHANNEL

?Storage of 140 tons of carbon sequestrating 29 tons per year.

Stormwater Management:

Drainage from the 360-acre watershed west of Military Drive passes through a box culvert bridge beneath the roadway as it flows toward Leon Creek. The +5 acres present an opportunity to incorporate structural storm water best management practices (BMP's) to facilitate enhancing water quality while reducing the transport of pollutants within the Leon Creek Watershed through the inclusion of LID strategies. LID strategies being implemented include:

? Regenerative landscape - The integration of native and site appropriate vegetation including riparian, upland, and grassland species improving the viability of the site and reducing water usage.

? Biofiltration for removal of contaminants and pollutants from roadway and parking

SAN ANTONIO, TX

TRANSPORTATION CITY OF SAN ANTO&NCAPITAL IO TRANSPORTA ITIMOPNRO&VCEAMPIETNATLS P.O. BMOUIVXNEI8M3CR9IP9TP6IRA6CLOAPVVLLEEASDRZAIMTANVIEIBACSUNINIATLTOLODSNIDNIINOGV,I1TS1I4XOW.NCOMME78R2C83E-3966

MUNICTIEPL.A (L2P10L)A2Z07A-2B87UI9LDING 114 W. COMMERFCAEX (210) 207-2197

CITY OF SAN ANTONIO

? Leave a lasting first impression on the thousands of family members of freshly-minted Air Force Cadets and ? Integrate vehicular traffic into an efficient and complete street that supports pedestrians, bicyclists, and

users of public transportation.

CORRIDOR GATEWAY PHASE 1:

In October 2014, the City Council allocated funding for Phase 1, the Lackland Corridor Gateway, to serve as a catalyst to stimulate the urban vitality of the community surrounding JBSA-Lackland. To provide a place of `lasting impression' in a well-designed environment, the corner of US Hwy. 90 and SW Military Drive--the most visible location along the Corridor as the gateway to Lackland Air Force Base- was chosen as the site. The site, partially owned by TxDOT and partially by the Joint Base San Antonio (Air Force), will be transformed into a park setting by a City of San Antonio capital improvements project. In November 2015, the Council accelerated funding for the complete site design and construction with an aggressive 6-month design schedule. The project is currently in final negotiation with the contractor with an anticipated construction schedule of 6 months. Construction is slated to begin in November 2016. The City of San Antonio Parks department will assume maintenance of the project after the contractors 1 year warranty period ends. Total project funding has been allocated at $6.1 million.

BIORETENTION SECTION A

ELEV. 745

3

C-27.0

12" OVERFLOW

1

C-26.0

3

740

STA:0+13.69 C-27.0

ELEV:737.00

ELEV.

745

12" OVERFLOW

735

1:1 SLOPE

740 730

STA:0+13.69 ELEV:737.00

30 MIL PVC

735 725

0+00 730

LINER

1:1 SLOPE 3' THICK

BIORETENTION MEDIA 30 MIL PVC LINER

725

0+00

3' THICK

BIORETENTION MEDIA

1

STA:0+42.69 ELEV:737.00

C-26.0

STA:0+42.69 ELEV:737.00

STA:0+36.37 ELEV:731.42

STA:0+36.37 ELEV:731.42

ELEV. 745

30 MIL PVC LINER 740

SITE WALL TYPE 2

ELEV.

BEND

745 735

BEND

STA:0+81.34

30 MIL PVC LINER 12" OUTFSAILTLE WALL TYPE 2

ELEV7:74301.07 730

MIN. 12"

?3' ?3'

2

C-260.0+50

MIN. 0.5% SLOBPEEND

BEND

735 725 STA:0+81.34

0+87 ELEV:731.07

12" OUTFALL MIN. 0.5% SLOPE

36" RECLAIMED 730

WATER LINE

MIN. 12"

2

725

C-260.0+50

0+87

36" RECLAIMED

WATER LINE

BIORETENTION SECTION B

Site Enhancements - Consistent with the Lackland Corridor Streetscape Conceptual Master Plan (2014 RVK), the development of the most visible location along the corridor known as the Gateway Project. A five acre parcel at the intersection of U.S. Highway 90 and SW Military Drive accepts and carries drainage from a larger watershed west and north of the site. A paved channel bottom transitions to a full concrete channel southeast of the site and northeast of JBSA Lackland proper. Design enhancements include but are not limited to the following:

HWY 90

STA:0+52.32

STREAM RESTORATION PLAN

EXISTING INLET

745

ELEV:738.43

STA:0+45.77 ELEV:736.25

PEDESTRIAN

BRIDGE 745

STA:0+62.72

HWY 90

PONDING

STA:0+45.77 STA:0+52.32

ELEV:738.19

740 ACCESS ROAD

ELEV: 737.00

ELEV:736.00 ELEV:738.43

740

FLOW FROM ROAD EXISTING INLET 735 745 EXISTING CONCRETE

STA:0+45.77 ELEV:736.25

HTWOYR9E0MAIN

PONDING

STA:0+45.77

740 730

ANCOCNE-WSSORVEONADGEOTEXTILEELEV: 737.00

ELEV:736.00

FILTER FABRIC

STA:0+38.82

PEDESTRIAN

BRIDGE

MULCH

745

735

STA:0+62.72

STA:0+44.60 ELEV:735.25

ELEV:738.19 740 730

MULCH

735 725

0+00

TXDOT 730

725

STA:0+38.57 EXISTING COENLCEVR:E7T3E5.25

TO REMAIN

ELEV:735.00

STA:0+44.35 ELEV:735.00

735 725

FOREBAY AND

0+50

NON-WOVEN GEOTEXTILEENERGY DISSIPATER

FILTER FABRIC

PROFILESTBA:M0+P38.257

FOREESBLTEAAV:0Y:+733-58..08V02ERT

SCALE

1"

=

10'

ESLTEAV:0:+734054..+265070 MIN. 2 LAYER

-

47"-360"

CRUSHED

STA:A0+N4G4U.3L5AR LIMESTONE

ELEV:735.25

ELEV:735.00

725

CONCENTRATED PROPERTY 0+00

FOREBAY AND

0+50

ENERGY DISSIPATER

0+70

FLOW FROM OFF-SITE PROFILE BMP 2 FOREBAY - VERT SCALE 1" = 10'

MIN. 2 LAYER - 4"-6" CRUSHED ANGULAR LIMESTONE

300 ACRE WATERSHED

MILITARY DR SW

SW LACKLLAACNKDLACNODMILITARY RRCIODRORR&I USDGAOHWY TREG90WAATYEWAY SW MILITASRAYN &ANUTSOHNIWOY, 9T0EXAS BISOARNEATENTNTOINOINO,BTAESIXNASBMP 2 SECTIONS

P.O. BOX 839966

TEL. (210) 207-2879

BIORETENTION BASIN BMP 2 SECTIONS

JBSA PROPERTY

SINGLE DROP CROSS VEIN DETAIL 2

Revised Results 2 Year Event Depth

CHANNELED FLOW CONTINUES TO LEON CREEK

C

24.0

C

Designed By:

TD/LOB

24.0

Drawn By:

RM

Date:Designed By:

07/19T/2D0/1L6OB

ProjecDt rNawo.n: By:

WBSR2M3-01455

FilenaDmaete: :

07/19/2016

Project No. :

WBS 23-01455

Filename:

FLOW OVERBANKING & UNDERMINING SIDEWALL OF CHANNEL

2-YEAR EVENT Modeling the 100-Year Lackland AFB Corridor Gateway -ESvTeRnEt AtoMCRhEeScTkORoAvTeIrObNan3Dk MODEL

stability

lot paving via three bioretention features ? two located along the street frontage and one within the site treating storm water runoff from the parking lot ? Impervious cover limits ? Building materials - limiting the use of materials that contribute to water pollution ? Shade structure canopy runoff diversion to bioretention area ? Floodplain Depressions- include vegetated swales, detention/infiltration basins with biotic habitat. ? Litter control ? Waterway/stream naturalization to replace a poorly functioning concrete channel with a stable healthy stream.

The transformation starts with removing 900 ft. of existing poor functioning concrete stormwater drainage channel

and lifting it to a higher functioning ecological state through stream restoration. The restoration will reduce stream

velocity and reconnect the stream to its floodplain to reduce downstream flooding. The stormwater treatment plan

involves restoration of the channel to provide ecological uplift, shading of the stream and floodplain depressions that

will reduce velocity and trap sediment. Although this project will modify the stream channel, the overall impacts will

25

be positive for water quality and stormwater management. The onsite stormwater management features will serve to

reduce runoff, improve water quality, capture floatables and sediment and reduce the flashy nature of urban roadway

runoff. This is especially true for smaller storm events that create most of the erosion and cause the majority of stream

stability issues that lead to flooding problems. Furthermore, in compliance with E.O. 11988 and E.O. 13690 and the

subsequent guidelines release by FEMA and the USACE, the planning and design process for this project will result

in meeting the goal "to restore and preserve the natural and beneficial values served by floodplains". By removing

the concrete channel through the majority of the site, past federally funded actions that removed the natural stream

function will be mitigated resulting in a net benefit to floodplain.

The onsite stormwater management plan includes three bioretention areas to capture and treat the first 1.5 inches of

runoff. Two bioretention areas will capture the 90th percentile storm (1.5 inches) from adjacent roadways that drain

? Storm water improvements to existing channel ? stream naturalization

? Storm water management including area planted LID features in its final

? Restroom Port a Unit with its enclosure ? 75' Monument (Tribute) by local artist George

Schroeder, lit at night with LED light fixtures ? Walkways with Two architectural pedestrian bridg-

BMP - PARK SITE

Existing Conditions

"TRIBUTE" SCULPTURE

Lackland AFB Corridor 1Ga0tew0ay-YEAR EVENT - FLOOD PLAIN 3D MODEL

through the site, reducing pollutant loads, reducing erosion, and mitigating the peak flow effects from impervious cover. The third bioretention area will mitigate the impact of the parking lot, driveway, restroom, and walkways that 28 are being added to the site. All three bioretention areas will have underdrains due to the high groundwater and clay soils onsite. The underdrains will slowly release clean runoff into the stream to provide high quality base flow.

configuration161 Trees with automatic bubbler irrigation system for establishment

es Sidewalks ? Three overlook nodes with interpretative graphic

NATIVE GRASSES

? 161 Trees with automatic bubbler irrigation system for establishment Picnic unit with shade canopy

? Area Parking (19 spaces) ? Picnic unit with shade canopy

panel and seating area ? Entry Wayfinding Sign

BIORETENTION BASIN

ART:

The focus of the gateway, the monumental sculpture- TRIBUTE, serves as an icon associated with Lackland Air Force Base within the City of San Antonio. The sculpture, created in collaboration between the Project Landscape Architect and local Artist George Schroeder, consists of five forms. The arrangement creates a gathering space intended to be dynamic and interactive as it can be touched, walked within and around. Its aesthetic is that of an airplane and by riveting the aluminum cladding to the substructure, it replicates aircraft construction. With the forms seemingly rising out of the ground, the monument captures light, reflects the sun and casts large shadows.

DESIGN PRINCIPLES:

The central guiding objectives for the design include: ? Increase levels of safety and enhance the perception of safety, ? Highlight pedestrian and bicycle connections, ? Enhance and generate memorable places,

STREAM RESTORATION

UPLAND HABITAT BIORETENTION BASIN

BIORETENTION BASIN BUTTERFLY & HUMMER PLANTINGS

The tallest element is an obelisk-type form reaching 75' high representing our country and the community of San Antonio. The narrowest edge of the obelisk is aligned to our nation's capital paying homage to Washington, D.C. The three arched forms represent the arms of the military protecting our great Nation. Each arm displays one of the three Core Values of the United States Air Force. The fifth element serves as the direct reference to Lackland Air Force Base. The form representing a wing is intentionally placed at an angle to contrast with the other elements, contributing to the visual tension of the overall piece. From dusk to dawn, the experience of the gateway is enhanced through the use of LED lighting. Six days a week, white light will illuminate the sculpture. On Fridays, to celebrate the weekly graduation of over 500 new Airmen, United States Air Force blue will illuminate the interior space of the sculpture proclaiming the significance of this day.

? Create an environmentally sound urban space using low impact techniques, facilitate ecosystem services

STREAM NATURALIZATION

BUTTERFLY & HUMMER PLANTINGS

? Lay the foundation for a future corridor streetscape to mature and last the test of time ? Improve economic vitality of the area.

RIPARIAN CORRIDOR

SWITCH GRASS FROG FRUIT SCARLET SAGE

NATIVE TRAIL MIX SEEP MUHLY

SWITCH GRASS

INTERPRETIVE OPPORTUNITIES:

The site will include interpretive signage to inform visitors of the LID features and their benefits to both human and wildlife habitat. The four interpretive

GRANT:

The design team submitted a LID grant application to the San Antonio River Authority on behalf of the City of San Antonio. The project was awarded a $100,000 grant through a competitive process. SARA will also verify performance and viability of the BMPs for up to two years after construction is completed.

INTERACTIVE BIORETENTION PLAN

Proposed Development

COBBLE R-I-P RAP

INTERACTIVE BIORETENTION PLANTING PLAN

SEEP MUHLY NATIVE TRAIL MIX SCARLET SAGE FROG FRUIT OBEDIENT PLANT

opportunities encompass three overlook nodes around the perimeter of the stream basin and specific planting areas. The graphic panels afford the

opportunity to learn about: ? The role of the military to San Antonio and inspiration behind the monument. ? Low Impact Development (LID) systems, ? Channel realignment and naturalization of the drainage way ? Carefully selected vegetation and also a butterfly habitat for the endangered Monarch butterfly, as well as migrating birds, supporting our City Mayor Ivy R. Taylor's commitment as the first Monarch Champion participating in the National Wildlife Federation's Mayor's Monarch Pledge.

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download