APPENDIX D WOODS RUN STREAM INFLOW ...apps.pittsburghpa.gov/pwsa/Appendix_D_-_Woods_Run_Stream...WOODS RUN STREAM INFLOW EVALUATION, DETENTION LOCATION A Modeling showed that a 0.16

355310 PWSA City-Wide Green Infrastructure Assessment – Draft Report 11/10/16 D-1

APPENDIX D WOODS RUN STREAM INFLOW EVALUATION, DETENTION LOCATION A

Modeling showed that a 0.16 MG detention facility is required to handle flows from the 92-acre tributary runoff area from both inflow points shown in Figure D-1. These two inflow locations were grouped together based on close proximity, and have adjacent drainage areas.

Figure D-1: Woods Run Potential Inflow Detention Location A

ASSUMPTIONS AND PROJECT DETAILS

Project Siting Considerations: The land areas shown in Figure D-1 were selected due to their flat terrain and close proximity to the two direct stream inflow locations. It was assumed that the flat, non-developed parcel could be obtained and used for stormwater detention features.

Detention Overview: It was assumed that the parcel shaded in Figure D-1 could be used as a subsurface gravel wetland storage facility, due to the grading and depth needed to divert the stream into the storage. For cost estimating, approximate excavation depth was assumed to be a conservative 15-footdepth. The calculated storage depth, given the

DRFigure re D-1D-1: Woods Ruods R

SSUMPTIONS AND PROJSSUMPTIONS AND PR

Siting ConsidSiting Considrain andrain and

nono

FT


footprint area as shown, would be approximately 2.6 feet deep. This could be handled both through surface ponding and detention within the subsurface gravel storage layer.

The grading at this location appears to allow for both surface and subsurface storage.

Cost Estimate: An estimate is provided in Table D-1 outlining the typical project costs associated with the size and type of detention facility described above. A 40% planning contingency has been added to account for unknown factors not quantified in thesepreliminary planning level assumptions.

TABLE D-1 PLANNING LEVEL COST ESTIMATE FOR WOODS RUN DETENTION LOCATION A

DETENTION LOCATION B

This detention location would capture stormwater runoff from a 56-acre area. Runoff from both sides of the shed enters into the combined sewer system along Oakdale Street and conveyed south along the center of the sewershed. This location was best suited to capture flow in bioswale type BMPs within the right of way on either side of Oakdale Street.

Assumptions and Project Details

Project Siting Considerations: With no large flat areas to capture stormwater regionally at this location, distributed BMPs were laid out alongside Oakdale Street as shown in Figure D-2 below.

BMP Overview: Modeling showed that 0.5 MG of storage was required for this location to capture the largest storm event in the Typical Year. 20 BMPs were envisioned for this area,with each capturing 3,350 cubic feet (cf), or 25,000 gallons, of runoff at each BMP location. A total of 500,000 gallons of storage would be needed. For sizing and cost estimating,

DRTION LOCATION BTION LOCATION B

This detention location would capture This detention location would captboth sides of the shed enters into both sides of the shed enters into conveyed south along the centerconveyed south along theow in bioswale type BMPs wow in bioswale type BMP

mptions and Projemptions and Proje

ng Conng Conss

FTA 40A 4

quantified quanti

DETENTIODETE N LOCATION A LOCA


approximate dimensions of the required BMPs were assumed to be approximately 6 feet x 6feet x 100 feet length. This sizing conservatively does not take into account any infiltration.

Cost Estimate

An estimate is provided in Table D-2 outlining the typical project costs associated with the size and type BMPs described above. A standard high and low unit price per gallon of storage was applied to the total 500,000 gallon BMP volume to develop a cost range for this work. A 40% planning contingency has been added to account for the unknown factors not quantified in these preliminary planning level assumptions.

Figure D-2: Woods Run Potential Inflow Detention Location BDFigure DFigure D--22

FTrice price p

p a cost rangp a coshe unknown factohe unk

D


TABLE D-2 PLANNING LEVEL COST ESTIMATE FOR WOODS RUN DETENTION LOCATION B

DETENTION LOCATION C

The detention projects envisioned at inflow location C would be planned to handle the stream base flow from the Mairdale stream inflow point, as well as the wet weather peak flows for the Typical Year


Project Siting Considerations: As shown in Figure D-3, the stream inflow point enters a 36-inch diameter combined sewer on the northern side of Mairdale Street, and crosses perpendicular to Mairdale as it continues towards Woods Run Ave. A large, flat parcel of land, shown in Figure D-4, was identified across the street from the inflow point as a possible stormwater management location for this inflow point.

BMP Overview: The flat parcel of land identified above, along with two other locations forBMPs along the right-of-way, make up the 0.31 acres of footprint required to manage the stream base flow and 72-acre tributary area. Modeling showed that 0.35 MG of storage was required for this location to capture the largest storm event in the Typical Year.

It is anticipated that this location could function as tiered stormwater ponding and subsurface storage similar to the bioswale project installed in 2013 by others at Mt. Alvernia along Hawthorne Road in Millvale. Figure D-5 shows a possible layout for this location.DRAFTtion C C would be plannedwould be plann to handle the

nflow point, as well as the wet weathent, as well as

s: As shown in Figure own in Figure D-3D-3, t, the streahe stread sewer on the northern side of Mae northern side of Ma

le as it continues towards Woods Rue as it continues towards DD-4, -4, was identified across the street fwas identified across t

ement location for this inflow ement location for this inflow point. poi

w: The flat parcel of land identified a: The flat parcel of land identified ang the rightight--ofof-f wayway, , make up the 0.3make up the 0.3

base flow and 72e flow and 72--acre tributary area. acreired for this location to capture the largired for this location to capt

ItIt i is anticipated that this location coulds anticipated that this location coustorage similar to the storage similar to the bioswale bi ppHawthorne Road Hawth in Millvale. llva Fi


Figure D-3: Woods Run Inflow Detention Location C

DRAFTre re D-3D-3: Woods: Woo Run Inflow DetentionInflow


Figure D-4: Close-Up of Woods Run Inflow Detention Location C

Figure D-5: Envisioned Layout for Potential Bioswale at Detention Location C

DRACloseClose--Up of WoodsUp of Woods

TRun Inflow DeteRun I


Cost Estimate

An estimate is provided in Table D-3 outlining the typical project costs associated with the size and type of surface and subsurface storage described above. A 40% planning contingency has been added to account for the unknown factors not quantified in thesepreliminary planning level assumptions.

TABLE D-3 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DETENTION LOCATION C

DETENTION LOCATION D

BMP location D is located in the one drainage area evaluated in this section that is not considered a stream inflow location. Rainfall runoff from the Benton Field Park is captured in a separate storm sewer system and routed to the combined sewer system along Woods Run Avenue. This sewershed was identified as a good location to intercept and manage the stormwater upstream of the discharge location into the combined sewer system.


Project Siting Considerations: As shown in Figure D-6, the Benton Field sewershed covers a 40-acre area consisting of parks, some residential housing, and a wooded area. Downstream of the residential and park areas, an open and relatively flat area, shown in Figure D-7 was identified as a possible stormwater management location to intercept the storm sewer flow. Alternatively, there is an unpaved road connecting the park to Woods Run Avenue in which the alignment could be used to site distributed BMPs along the roadside.

DRENTION LOCATION DENTION LOCATION D

BMP location DBMP is located in the located in the ooconsidered a stream inflow locatioconsidered a stream inflow locatioa separate storm sewer systema separate storm sewer sy

enue. This sewershedenue. This sewershed wwater water upstream of tupstream of

ons and ons and

FTDETENTIODETENTION LOCATIONN


BMP Overview: A flat section of land near the junction location of the storm sewer pipes was selected as a possible location for surface detention. Because the storm sewer depths and surface have not been surveyed, assumptions for slope and grading were made in selecting this storage type.

Figure D-6: Woods Run Stormwater Runoff Detention Location D

DRFigure DFigur -6:6:

TWoods Run StormwWoo


Figure D-7: Close-Up of Woods Run Stormwater Runoff Detention Location D

Cost Estimate

An estimate is provided in Table D-4 outlining the typical project costs associated with the size and type of surface detention described above. A 40% planning contingency has been added to account for the unknown factors not quantified in these preliminary planning level assumptions. DRAFT

sese--Up of Woods Run Stormwater RUp of Woods Run Storm

mate

estimate is provided estimate is provi in Tin Table Dab -4 outlze and type of surface ze and type of surfac detention descetention

addedadde to account for the unknown for the unknown assumptions. assu


TABLE D-4 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DETENTION LOCATION D

DETENTION LOCATION E

BMP Location E is planned to intercept wet weather runoff from a 66-acre area covering parts of Riverview Park. The runoff follows a shallow ravine and enters an inflow point to the combined sewer system behind the houses near 915 Woods Run Avenue. During field visits in 2015, base stream flow was not observed at this location.


Project Siting Considerations: The contributing park areas consist primarily of wooded area, along with runoff contributed from the Riverview Avenue road through the park. This drainage area is made up largely of steeply sloped hillsides, however, a few locations were identified for BMPs. Towards the middle of the drainage area, there is a flat section of land near where Riverview Avenue makes a sharp bend. This large, flat, and undeveloped parcel has the potential to be used to manage wet weather flows from the upper sections of the park. Additionally, there is a private drive near the downstream end of the shed where BMPs may be able to be sited. These physical features and the potential detention location are shown in Figure D-8.

BMP Overview: For this analysis, it was assumed that 50% of the required 0.22 MG of storage would be captured by the regional subsurface detention, with the other half of the flow being captured by the distributed BMPs sited at the downstream section of the shed.

DRAFN EN E

s s plannedplan to intercept wet weather rntercept wet weaew Park. The runoff follows a shallow ew Park. The runoff follows a shallow

ewer system behind the houses near 9system behind the houses near 9base stream flow was not observed at m flow was not observed at

umptions and Project Detailsumptions and Project Det

Project Siting Considerations:Project Siting Considerations: ThTarea, along with runoff contributearea, along with runoff codrainage area is made up largdrainage area is made up

ntified for BMntified f Ps. TowardTowa

T

where Riverview Avwhere Riverview Aotential to botential to b

nally, nally,


Figure D-8: Woods Run Inflow Detention Location E

Cost Estimate

Tables D-5 and D-6 provide cost estimates for both the subsurface detention as well as the distributed BMPs. A 40% planning contingency has been added to account for the unknown factors not quantified in these preliminary planning level assumptions.

TABLE D-5 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DISTRIBUTED BMPS

FOR LOCATION EDRAgure Dgure D-8: Woods Run Inflow DetenWoods Run Inflow t

ate

D-5 D-5 and and D-6 providerovide cost estimatesc foibuted BMPs. ibuted BMPs. A 40% planning continA 40% planni

Tactors not quantified in these preliminaactors not quantified in these prelim

PLANNING LEVEL COST EPLANNING LEVEL CO


TABLE D-6 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DETENTION LOCATION E

DETENTION LOCATION F

Detention location F is planned to capture stormwater runoff from the 90-acre area of land containing part of Riverview Park and Kilbuck Road.


Project Siting Considerations: The contributing park areas consist primarily of wooded area, along with runoff contributed from Kilbuck Road, which runs through the park. This drainage area is made up largely of steeply sloped hillsides with runoff flowing down Kilbuck Road, which bisects the shed. Towards the middle of the drainage area, there is a flat section of land located within the park area. This large, flat, and undeveloped parcel has the potential to be used to manage wet weather flows from the upper sections of the park. Additionally, distributed BMPs along Kilbuck Road were envisioned to capture a portion of the flow. These physical features and the potential detention location are shown in Figure D-9.

BMP Overview: For this analysis, it was assumed that 66% of the required 0.48 MG of storage would be captured by regional subsurface detention located within the park. The remaining 33% of storage volume could be met with the use of distributed BMPs along Kilbuck Road prior to the inflow point near the intersection of Rothpletz Street and Kilbuck Road.

DRAFlannanned to capture stormwater runoff fed to capture stormwa

rview Park and Kilbuck Road. rview Park and Kilbuck Roa

nd Project Detailsnd Project Details

ting Considerations:onsiderations: The contributinThe contributinong with runoff contributed from Kilbnoff contrib

age area is made up largely of steeplyage area is made up largeadad, , which bisects the shed. Towardwhich bisects the shed. T

section of land sectio located within the parkated within the papotential to be used to manage potential to be used to manage AddAdditionally, distributed BMPs itionally, distributed B

e flow. e flow. These physical feysica

rviewrview: Fo: Fo

T

d bed be


Figure D-9: Woods Run Inflow Detention Location F

Cost Estimate

Tables D-7 and D-8 provide cost estimates for both the subsurface detention as well as the distributed BMPs. A 40% planning contingency has been added to account for the unknown factors not quantified in these preliminary planning level assumptions.

TABLE D-7 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DISTRIBUTED BMPS

FOR LOCATION F DRAgure Dgure D-9: WoodsWood Run Inflow Detentnflow

te

D-7 D-7 and and D-8 D provideovide cost estimatesc fributed BMPs. ributed BMPs. A 40% planning continA 40% planni

Tfactors not quantified in these preliminafactors not quantified in these prelim

PLANNING LEVEL COST PLANNING LEVEL CO


TABLE D-8 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DETENTION LOCATION F

DETENTION LOCATION G

Detention location G captures flow adjacent to the BMP location F sewershed. This location largely captures stormwater runoff from the Highwood Cemetery, neighboring wooded areas, and a few residential streets.


Project Siting Considerations: Runoff from the cemetery and wooded areas travels through the undeveloped terrain in a shallow ravine to the location of a PWSA catch basin located near the intersection of Smithton Avenue and Henley Street. At present no open space is available for detention downstream of the inflow point. An opportunity was identified to site subsurface stormwater management features in the shallow ravine directly upstream of the inflow point between the cemetery and the existing PWSA catch basin.

BMP Overview: Modeling indicated that a 0.28 MG subsurface storage feature could effectively manage runoff from the 76-acre contributing area for the Typical Year wet weather conditions. This storage feature, as highlighted in Figure D-10, assumes 11,300 SF footprint, with an average depth of 3.3 feet for storage. The required storage depth could be met through a combination of surface ponding and subsurface storage. DRAF

res flow adjacent to the nt to the BMP BM locationcationater runoff from the Highwood Cemeteater runoff from the Highwo

streets. streets

nd Project Detailsnd Project Details

Siting Considerations:onsiderations Runoff fromunoff fromh the undeveloped terrain in a shallowthe undeveloped ter

ted near the intersection of Smithtonted near the intersection ofpace pace is available is available for detention dowfor detention

identified to site subsurface stormwidentified to site subsurface stormwupstream of the inflow point betwupstream of the inflow poi

MP OverviewMP Ove : Modeling odelinvely manage runovely manage runo

conditionsconditions. T. Th an avh an av

T


Figure D-10 Woods Run Inflow Detention Location G

Cost Estimate

An estimate is provided in Table D-9 outlining the typical project costs associated with the size and type of subsurface storage described above. A 40% planning contingency has been added to account for the unknown factors not quantified in these preliminary planning level assumptions. DRAgure Dgure D-10 WoodsWood Run Inflow Detentnflow

te is provided ded in Table in Table D-9 outlining thining thnd type of subsurface storage d type of subsurface st describe

eded to account for the unknown factorsto account for the unknow

Tassumptions. assump


TABLE D-9 PLANNING LEVEL COST ESTIMATE FOR THE WOODS RUN DETENTION LOCATION G

DRAF

T

Documents

APPENDIX D WOODS RUN STREAM INFLOW ...apps.pittsburghpa.gov/pwsa/Appendix_D_-_Woods_Run_Stream...WOODS RUN STREAM INFLOW EVALUATION, DETENTION LOCATION A Modeling showed that a 0.16