05 SP-2022-0537C - Lift Station No.53; District 6.pdf

Zoning and Platting Commission – April 2, 2024

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PLANNING COMMISSION ENVIRONMENTAL VARIANCES & CONDITIONAL USE SITE PLAN REVIEW SHEET CASE NUMBER: SP-2022-0537C PC HEARING DATE: April 2, 2024 PROJECT NAME: Northwest Area Lift Station Improvements Great Hills Lift Station No. 53 ADDRESS OF SITE: 9009-1/2 SPICEBRUSH DR COUNCIL DISTRICT: 6 NEIGHBORHOOD PLANNING AREA: NA WATERSHED: Bull Creek JURISDICTION: Austin Full Purpose APPLICANT/ OWNER: AGENT: City of Austin Austin Water Department Joe Hoepken (512) 972-1168 Sharon Hamilton Civil Team Engineers, LLC (512) 695-3263 CASE MANAGER: Meg Greenfield Meg.greenfield@austintexas.gov (512) 978-4663 PROPOSED DEVELOPMENT: The applicant is proposing the replacement of an existing lift station. This request is to approve three environmental variances and a conditional use site plan. Environmental variance requests: 1. Development in the CWQZ for a lift station per LDC 25-8-261 2. Construction of a building on a slope with a gradient of more than 25% per LDC 25-8-302(A)(1) 3. Fill up to 14 feet for construction of a lift station exceeding the 4-foot limitation per LDC 25-8- 342 The variances were approved with the following conditions by the Environmental Commission on March 6, 2024: 1. Limit construction and removal of trees from March to August when the endangered Golden-cheeked Warbler is in the area. 2. Applicant will solicit and incorporate Watershed Protection Jollyville Plateau salamander expert review and comment on the temporary and permanent stormwater design. 3. After construction, the disturbed areas from both this construction and previous emergency repairs are restored using 609S species and that those areas are maintained and mowed to the minimum extent practical to maintain access to the lift stations by Austin Water staff. Per 25-2-491 Local Utility Services is a conditional use in the SF-2 zone and requires a Conditional Use Permit. 1 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 SUMMARY STAFF RECOMMENDATION: Staff recommends approval of these requests with the following condition: Provide structural containment of the fill with a retaining wall. Staff does not believe Environmental Commission conditions are necessary. SUMMARY COMPONENTS OF SITE PLAN: All reviewers have approved the site plan except for environmental and site plan plumbing. PROJECT INFORMATION SITE AREA EXISTING ZONING FLOOR-AREA RATIO BUILDING COVERAGE IMPERVIOUS COVERAGE PARKING EXISTING ZONING AND LAND USES 33,637 sq. ft. SF-2 Allowed NA 40% 45% NA Proposed NA NA 23% NA 0.77 acres ZONING LAND USES Local Utility Services Single Family Open Space Single Family Single Family Right-of-Way Width 50 feet (variable) Pavement Width Classification Approx. 25 feet Suburban Roadway SF-2 SF-2 SF-2 SF-2 SF-2 Site North South East West ABUTTING STREETS Street Spicebrush Drive NEIGHBORHOOD ORGANIZATIONS: Austin Great Hills Homeowners Assn., Inc. Austin Independent School District Austin Lost and Found Pets Bull Creek Foundation Friends of Austin Neighborhoods Long Canyon Homeowners Assn. Mountain Neighborhood Association (MNA) Neighborhood Empowerment Foundation North Oaks Neighborhood Assn., SELTexas Sierra Club Austin Regional Group TNR BCP – Travis County Natural Resources Yaupon Bluffs Community Association 2 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Property Jurisdiction 1: 4800 FULL PURPOSE LIMITED PURPOSE EXTRATERRITORIAL JURISDICTION 3/28/2024 Jurisdictions Fill Jurisdiction FULL PURPOSE LIMITED PURPOSE EXTRATERRITORIAL JURISDICTION Zoning 1 Zoning Text This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. It does not represent an on-the-ground survey. This product has been produced by the City of Austin for the sole purpose of geographic reference. No warranty is made by the City of Austin regarding specific accuracy or completeness. 3 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 July 26, 2022 REVISED 9/19/2022 REVISED 11/16/2023 Mr. Roderick Burns City of Austin Development Services Department PO Box 1088 Austin, Texas 78767 Re: Engineer’s Summary Memorandum Northwest Area Lift Station Improvements CLMP246 SA190000008 Great Hills Lift Station Mr. Burns, We are pleased to present this new City project for a Site Plan Development Permit review. The project has progressed to 100% design at this time. We have addressed the comments received during the Site Concept Plan review DSD of the 90% design phase. Please advise what additional constraints we may need to navigate. INTRODUCTION The Great Hills Lift Station was built in 1985 and is located in a wastewater easement on a residential property at the rear of 9009 ½ Spicebrush Drive. The lift station is located at the end of a 300-foot driveway within a 20-foot wide access easement running between two private residences. The site lies in the Bull Creek watershed and is adjacent to a Bull Creek tributary. The site is approximately 15-feet north of the 100-year floodplain and is located entirely in the critical water quality zone. (See Exhibit 1 for a project site location map.) The grading leading to the existing site is steep and accessing the lift station equipment for maintenance with utility vehicles is extremely difficult. The improvement options include replacing the existing dry pit/wet well duplex station with a new wet well and submersible pumps. There are no future capacity increases associated with the new lift station, and the proposed options maintain the existing firm capacity. SCOPE This project is part of the Northwest Area Lift Station Improvements Program. The existing Great Hills Lift Station consists of two 10-foot diameter concrete wet wells and a 220-square foot dry pit approximately 31-feet deep, two 150-horsepower (hp) pumps, electrical 4 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 2 of 13 equipment and instrumentation panels, and a flowmeter vault located outside of the fence. Three gravity mains provide inflows to the lift station. Outflows are pumped through a 16-inch ductile iron force main. During the Feasibility Phase of the project, the decision was made by the COA to replace the existing dry pit/wet well “can” duplex lift station with a new submersible pump lift station in order to meet current City of Austin (COA) lift station standards and to prevent potential overflow discharges. In addition, improvements will be integrated in the design to improve site access to the lift station. Lastly, the existing lift station has been consistently meeting current demands, and future projected flows are not expected to exceed the existing capacity. See Exhibit 1 for a project site location map. As recommended in the Feasibility Report and accepted by Austin Water (AW), the East Option will be pursued – the new lift station will be built immediately to the east of the existing. The proposed site plan is provided as Exhibit 2. PROJECT CONTACTS The project contact list is provided in Table 1 below: Org. PHONE NAME AW Charles Celauro, PE AW Joanette Aird, EIT CDS Abhi Raghavan KFA Tom Owens, PE KFA Chris Leal, PE Sharon Hamilton, PE CTE ROLE Owner AW Sponsor City PM Consultant Principal Consultant PM Permit Assistance 512-972-0208 512-972-0185 512-974-7810 512-338-1704 512-338-1704 512-695-3263 Table 1: Project Contact List EMAIL charles.celauro@austintexas.gov joanette.aird@austintexas.gov abhi.raghavan@austintexas.gov towens@kfriese.com cleal@kfriese.com hamilton@civilteamengineers.com DISTRIBUTION FOR REVIEW The scope of work for the lift station project included impervious cover and does not appear to be eligible for general permit coverage. The distribution at the concept site plan level should include: • Case Manager • Environmental • Austin Water • Site Plan • Watershed • Erosion Hazard Zone • ERI (Rimrock) • Floodplain Public/CIP Projects Team Brad Jackson, Public/CIP Projects Team Lift station review Planner Detention / Drainage review Watershed Reviewer ERM / Geologist review Floodplain reviewer 5 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6O N E C O V E A N E M S A T S U M A C O V E IRON W OOD COVE E V O C A E H T I L C SPICEBRUSH DRIVE S P I C E B R U S H C O V E SITE ACCESS POINT PROJECT SITE U S 183 IH 35 VICINITY MAP: 1" = 10,000' SITE ADDRESS: 9009 1 AUSTIN, TX 78759 2 SPICEBRUSH DRIVE GIN R E C O V E PROJECT SITE O P 3 6 0 L O PUCCOON COVE E RIV S D S A R G E U L B YAUPON DRIVE GREYFEATHER DRIVE CYRILLA DRIVE GREAT HILLS LIFT STATION IMPROVEMENTS GREAT HILLS LIFT STATION EXHIBIT 1 PROJECT SITE LOCATION MAP E R I V R D O W E L F R U P S 0 100' 200' 6 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6GUPTA RANJIT B & ALKA BHANOT LOT 7 GREAT HILLS XXVI 8 6 6 667 666 665 4 6 6 3 6 6 2 6 6 6 1 6 EXIST 8" DI WWL 665 EXIST 8" DI WWL EXIST 8" DI WWL PROPOSED 2" POLYETHYLENE GAS LINE. GAS LINE AND METER TO BE INSTALLED BY OTHERS PROPOSED NATURAL GAS GENERATOR PAD 21'-6” x 10'-0” PROPOSED FENCE 6 6 2 K L EXISTING WASTEWATER MANHOLE #21750 RIM ELEV.=656.60' FL 8" DI IN=646.67' (NW) FL 8" DI OUT=646.04' (SE) JIB CRANE REACH 0 6 6 SWING GATES A B PROPOSED FENCE PROPOSED JUNCTION BOX RACK 12-FT (ID) WET WELL 6' WALK THROUGH MAN GATE 6 5 7 6 5 6 6 6 4 6 6 3 J 6 6 1 0 6 6 9 5 6 8 5 6 7 5 6 6 5 6 T S PROPOSED 18" PS115 PVC WWL N EXIST 8" DI WWL TO BE ABANDONED BH1 M O BOLLARD EXIST 12" WWL TO BE ABANDONED IN PLACE JIB CRANE U PROPOSED VALVE VAULT HATCHES BH2 F 6 6 7 6 6 6 5 6 6 4 6 36 6 6 662 661 660 6 5 9 6 5 8 C D E PROPOSED CONTROL ENCLOSURE 6 5 5 6 5 4 6 5 3 6 5 2 6 5 1 6 5 0 6 4 9 6 4 8 6 4 7 6 4 6 6 4 5 6 4 4 6 4 3 BH3 641 R PROPOSED 16" CL-350 DI FM PROPOSED 12" SDR-26 PVC WWL PROPOSED 12" SDR-26 PVC WWL Q PROPOSED 4-FT DIA PRECAST MANHOLE #3 EWING MANUELA & GREGORY R LOT 5 GREAT HILLS XXVI PROPOSED 5-FT DIA PRECAST POLYMER MANHOLE #1 PROPOSED 5/8" METER 6 5 6 I EXISTING WATER LINE TAP PROPOSED RPZ BACKFLOW PREVENTION VALVE (SEE DETAIL ON SHEET C21) PROPOSED 2" PVC SCH 40 WATERLINE CONTRACTOR TO RELOCATE AND ADJUST HOSE BIB TO MATCH PROPOSED GRADE AND LOCATION SHOWN (SEE DETAIL ON SHEET C21) PROPOSED 15" SDR-26 PVC WWL CONCRETE ELECTRICAL PAD TO BE REMOVED H 655 654 653 652 651 6 5 0 6 4 9 6 4 8 647 646 100-YEAR FLOODPLAIN 645 644 643 642 641 640 EXIST FORCE MAIN TO BE ABANDONED IN PLACE (CUT & PLUG) EXIST 8" WWL TO BE ABANDONED IN PLACE 639 PROPOSED 5-FT DIA PRECAST MANHOLE #2 BLAKELY DAVID LOT 6 GREAT HILLS XXVI EXIST 8" PVC WWL EXIST 8" PVC WWL INSTALL PROPOSED 6-FT DIA CAST IN PLACE VAULT WITH ULTRASONIC FLOW METER ON EXISTING FORCE MAIN. SEE DETAIL ON SHEET C17. CREEK ℄ REMOVE EXISTING FLOW METER VAULT. EXIST 16" DI FM 100-YEAR FLOODPLAIN PROPOSED CONCRETE RETAINING WALL P EXIST 12" PVC WWL 642 PROPOSED VALVE VAULT G PROPOSED 4-FT DIA PRECAST MANHOLE #4 100-YEAR FLOODPLAIN 0 VERTICAL SCALE IN FEET 10 20 HORIZONTAL SCALE IN FEET SCALE: 1" = 10' LEGEND PROPOSED CONCRETE PAVEMENT I I I I N N O O T T P P R R C C S S E E D D N N O O S S V V E E R R I I I I E E T T A A D D Y Y B B . . V V E E R R . . O O N N 100% SUBMITTAL THIS DOCUMENT IS RELEASED FOR THE PURPOSE OF INTERIM REVIEW UNDER THE AUTHORITY OF CHRISTOPHER M. LEAL, P.E. LIC. # 97373 3/18/2022 IT IS NOT TO BE USED FOR CONSTRUCTION, BIDDING OR PERMIT PURPOSES. S A X E T , I N T S U A F O Y T C I R E T A W N T S U A I I I I I N O S V D S E C V R E S G N R E E N G N E I I S T N E M E V O R P M I I I N O T A T S T F L A E R A T S E W H T R O N 3 5 . I O N N O T A T S T F L S L L H T A E R G I I I T U O Y A L E T S N O T A T S T F L I I NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY DRAWN BY DRAWN BY JRW 02/22 DESIGNED BY DESIGNED BY TJK 02/22 CHECKED BY CHECKED BY CML 02/22 REVIEWED BY REVIEWED BY C8 SHEET 14 OF 58 1 E M A N T E E H S 2 E M A N T E E H S . B T S D S E _ A O C , E P A C S D N A L _ 7 1 X 1 1 _ A O C , \ \ I . I G W D E T S - 0 6 7 0 \ S T E E H S N G D N G S E D _ S L _ S L L H _ T A E R G _ A O C _ 0 6 7 0 S T C E J O R P \ I \ : X M A 8 3 : 0 1 2 2 0 2 / 9 / 6 G I L L I W Y D U J 7 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 5 of 13 CITY OF AUSTIN PERMITTING TOPICS Trees, Tree Surveys, Tree Protection Aerial photos of this work site show many trees surrounding the lift station. Tree survey information is provided on the site plans. Note that a tree removal application was processed in early 2021 to allow for tree removals necessary to provide access for equipment to perform geotechnical bores. Some trees shown on the aerial below no longer exist on site. Per LDC 25-8-602, Trees 19” diameter and larger are defined as Protected trees, and trees with 24” diameter and larger are considered Heritage trees (Texas Ash, Texas Madrone, Bald Cypress, Bigtooth Maple, Cedar or American Elm, Pecan, Arizona Walnut, Eastern Black Walnut, or any Oak species). Figure 1: Aerial Photography Showing Tree Canopy, 2018 8 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 6 of 13 Edwards Aquifer There are two separate regulatory programs for areas over the Edwards Aquifer – City of Austin, and State of Texas through the Texas Commission on Environmental Quality (TCEQ). TCEQ Edwards Aquifer Rules and Program According to the Texas Commission on Environmental Quality (TCEQ) the work site is not within the Edwards Aquifer Recharge or Transition Zone, as shown in Figure 2. An Edwards Aquifer Protection Plans (EAPP) is NOT required to satisfy TCEQ requirements. No Action is needed to comply with the Edwards Aquifer Protection Program regulated by TCEQ. Figure 2: TCEQ Edwards Aquifer Viewer 9 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 7 of 13 City of Austin Edwards Aquifer Rules According to the COA, the site is not within the Edwards Aquifer Recharge Zone but is within the Edwards Aquifer “Recharge Verification Zone” as shown in Figure 3. The “mint” green striped area is recharge zone. No karst features were identified during the environmental feasibility study in February 2020. **Please provide information as to how the recharge verification zone should be addressed. EARZ Figure 3: COA EA Recharge Zone (Left) and COA EA Recharge Verification Zone (Right) Verification Zone Edwards Aquifer Recharge Not EARZ Watershed And Watershed Regulatory Area The work site is within the Bull Creek watershed. Reference LDC 25-8-2(D)(8)(a) for more information. The Bull Creek watershed is regulated as a Water Supply Suburban watershed. Refer to Figure 4 for boundaries of the Water Supply Suburban regulatory area in the vicinity of the project. 10 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 8 of 13 WATER SUPPLY SUBURBAN SUBURBAN URBAN WALNUT CREEK BULL CREEK SHOAL CREEK LITTLE WALNUT CREEK Figure 4: Watershed Regulatory Area (Top) and Watershed (Bottom) 11 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 9 of 13 Waterways / Creeks The project is bordered by a waterway known as Bull Creek, noted as a major waterway on the Property Profile viewer. Light blue lines indicate storm water conveyance via culverts, pipes, creek channels and waterways in Figure 5. Critical Water Quality Zone The critical water quality zone extends from the centerline of Bull creek for 200 feet, encompassing the entire lift station site. In a water supply suburban watershed, development within these zones is severely limited. The CWQZ is shown in Figure 5 as a hatched 200-foot-wide zone paralleling the creek centerline, on both sides of the creek. AW needs to keep the existing lift station operating during construction of the new lift station – this prevents replacement at the exact same location as the existing lift station. A variance will likely be required. **There is no feasible option to relocate the lift station outside the CWQZ on this lot and we will be requesting a variance to LDC §25-8-261 to place the lift station in the CWQZ. Water Quality Transition Zone The water quality transition zone is 300 feet wide and parallels the critical water quality zone, extending from the north side of the lift station across the entire residential lot, and on to the far side of Spicebrush Drive. Edge of WQTZ Edge of CWQZ Creek Centerline WQTZ CWQZ CWQZ WQTZ Figure 5: Water Quality Zones 12 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 10 of 13 Erosion Hazard Zone Work site locations within 100 feet of the centerline of a waterway will trigger the requirement for an analysis of the erosion hazard zone. The erosion hazard zone is an area defined as likely to erode and infrastructure must be vertically positioned below the erosion hazard zone - or protected to mitigate the risk of erosion. The erosion hazard zone is a relatively new regulation that was not in place at the time of construction of the existing lift station. The work site is impacted by buffer zones for erosion hazard zone review, as shown in Figure 6. The buffer where review of the EHZ must occur is shown as a tan ribbon that follows waterways. **The erosion hazard zone depth and width during final design has been calculated and is provided as an appendix to this report. EHZ Review Buffer Figure 6: Erosion Hazard Zone Review Buffer - Analysis Required 13 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns July 26, 2022 Page 11 of 13 Floodplain There are two separate regulatory programs currently in effect for areas of Austin known to be at risk of flooding. The Federal Emergency Management Agency (FEMA) and the City of Austin (COA) each have floodplain mapping. See Figure 7 for mapped floodplain areas. City of Austin Floodplain Mapping The City of Austin uses the FEMA maps for the purposes of applying current regulations to development. The COA is has adopted new design storm data provided by the National Oceanic and Atmospheric Association (NOAA) under the title “Atlas 14”. ATLAS 14 The Atlas 14 information updates the design storm to reflect climate data from the last several decades - data that was not available when FEMA maps were produced. However, the NOAA Atlas 14 reports did not perform drainage area analysis or provide new mapping of floodplains using the new design storm. The City of Austin has reviewed the Atlas 14 storm data. Knowing that drainage analysis has not been fully updated with the Atlas storm, the COA has decided that as an interim measure, the Atlas 14 data can be paired with the FEMA maps to provide new City maps. Staff can utilize the more current Atlas 14 data and give direction for development without waiting for city-wide drainage analysis. Two conclusions are presented at this time, as follows • The FEMA-mapped 100-year floodplain line approximately represents the real-world, current 25-year floodplain. This means the floodplain that would be mapped if an updated drainage analysis was performed using the new Atlas 14 storm for a 25-year occurrence interval over the known drainage areas of Austin. Therefore, City maps can be updated to use the dated 100-year FEMA line as the new 25-year City of Austin floodplain. • The FEMA-mapped 500-year floodplain line approximately represents the real-world, current 100-year floodplain. “Real-world” means the floodplain that would be mapped if an updated drainage analysis were performed using the new Atlas 14 storm for a 100-year occurrence interval over the known drainage areas of Austin. Therefore, City maps can be updated to use the dated 500-year FEMA line as the new 100-year City of Austin floodplain. The southern edge of the lift station site is within City floodplain mapping for the 100-year storm, but no work is planned within the floodplain. Refer to Figure 7. These GIS mapping features of FEMA 100-yr and 500-yr floodplain have also been added to the design plans Sheet C2 – Environmental Features. 14 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 New (Atlas 14) COA Fully Developed 25-yr and FEMA 100-yr (Blue) New (Atlas 14) COA Fully Developed 100-Year and FEMA 500-year (Turquoise) Figure 7: Floodplain Map at Great Hills Lift Station Flood Plain Review Based on our hydrological review and analysis, the contributory drainage area is approximately 1.15 acres for the delineated drainage area. See attached EXHIBIT and associate calculations. Based on the Peak Flow Analysis and Hydrological Analysis, there is a minimal discharge increase resulting from the proposed impervious cover additions to the site (wet well, valve vault, equipment pad, etc.). Due to this, we will need to participate in the COA RSMP Program. An application will be prepared. Critical Environmental Features Critical environmental features (CEFs) are not noted on the City’s property profile viewer within the immediate project area. This viewer shows information about CEFs that have been identified by previous projects. The information presented in the viewer should not be considered an exhaustive inventory, as it is not based on field work, and is not a complete verification of the existence of CEFs. Field work must be performed to determine if CEFs are present within the LOC, and within an additional 150 feet past the LOC. While Civil Team Engineers and K Friese + Associates have not performed field work to investigate CEFs, Blanton & Associates has performed this work and identified two critical environmental features in the vicinity of the existing lift station site. Both rimrock features appear to be outside the proposed project area at this time. However, it does appear that work will occur within the 150-foot prescribed buffer for these rimrock. Figure 8 includes a screenshot of the mapped CEFs in the Blanton Report. 15 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Mr. Roderick Burns August 18, 2021 Page 13 of 13 The Environmental Resource Inventory (ERI) document was prepared and submitted. Additionally, two (2) variances are requested to work within the prescribed buffers for two (2) rimrock. Figure 8: Critical Environmental Features (CEF) – Rimrock (See Red Lines) Image courtesy of Blanton & Associates Environmental Feasibility Report, February 2020 If for any reason during the site plan review, there are any questions or concerns that we can assist with, please feel free to contact me at (512) 338-1704 or via email at cleal@kfriese.com . Sincerely, Christopher M. Leal, PE Project Manager 11/16/2023 16 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6SPICEBRUSH Legend Proposed drainage area Proposed Pavement Proposed Pervious cover Existing Pavement Sheet Flow Shallow Flow 2 feet contours Creek Centerline City of Austin Great Hills Lift Station Drainage Area Map Ü 0 50 100 1 inch = 100 feet Date: 9/19/2022 FIRM NO. 6535 17 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Drainage Area Area (Ac) Grass/Parks Area (Ac) Pavement Total Area Cw Tc Calculated (min) Intensity (I) (in/hr) Computed Discharges (Q) (cfs) EXIST PROP 0.76 0.74 0.39 0.41 1.15 1.15 0.56 0.57 0.60 0.61 0.68 0.69 10.5 10.5 7.36 7.36 9.05 9.05 11.91 11.91 4.73 4.79 6.26 6.34 9.29 9.40 10-YR 25-YR 100-YR 10-YR 25-YR 100-YR 10-YR 25-YR 100-YR 2-Yr 2.82 2.86 2-Yr 0.50 0.51 Hydrological Analysis Summary Tc Used (min) 10.5 10.5 2-Yr 4.93 4.93 18 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 APPENDIX A: Erosion Hazard Zone Memorandum 19 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6MEMORANDUM Common Sense. Teamwork. Expertise. To: Christopher M. Leal, P.E. From: Cesar Calderon Jr, P.E. CC: Date: Re: July 25, 2022 Great Hills Lift Station – Erosion Hazard Zone Analysis Memorandum K Friese + Associates hired Civil Team Engineers (CTE) to provide professional engineering services for the Great Hills Lift Station Project, which included developing the Erosion Hazard Zone (EHZ) boundaries for the proposed lift station. This memo will summarize the data collected, the defined EHZ, and the relationship between the lift station and the EHZ boundaries. Data used included 2’ contour data from the City’s Property Profile for the area as seen in Figure 1, which also shows the EHZ that the Property Profile shows for the area. This topographic data along with planimetric data including existing utilities, stream centerline, and aerial photo was used to develop a base map. The topographic data was used to define a Level 1 Erosion Hazard Zone according to the City DCM – Appendix E. Per the criteria, a channel width of 80 feet at the lift station placement was measured between the assumed top of banks. Per the DCM guidelines, cross section spacing was 800 feet adjacent to the proposed lift station placement with the stream, 800 feet upstream of the lift station and 800 downstream of the station. Cross sections can be seen in Figure 2. Using the property profile tool, the length of the valley was measured and compared to the length of the channel. The sinuosity of the channel was determined to be 1.14 (Figure 3), therefore, a straight stream. Low bank elevations were determined for each cross section and each cross section’s top width, cross sectional area and channel depth was determined. The average channel depth was 1.54 feet. Per DCM guidelines, the average channel depth is multiplied by three to obtain the future incised bed elevation. The future incised bed elevation was completed for each cross section as seen in Figure 2. Then a four horizontal to 1 vertical slope was drafted from this elevation to existing ground. The intersection of the four to one vertical slope and existing ground is the erosion hazard boundary for each cross section. A line was then interpolated between each cross section representing the proposed erosion hazard zone boundary as see in Figure 2. NOT FOR CONSTRUCTIONTHIS DOCUMENT IS RELEASED FOR THE PURPOSEOF INTERIM REVIEW UNDER THE AUTHORITY OF:CESAR CALDERON JR, P.E.TEXAS NO:107183 ON DATE: 7/25/2022IT IS NOT TO BE USED FOR CONSTRUCTION, BIDDINGOR PERMIT PURPOSES.20 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6At the proposed lift station and manhole placement, the future incised bed level is 634.38 feet and the subsurface erosion hazard zone is 633.38 feet at the creek. The boundaries of the EHZ are noted in the profile for the cross section of the lift station in Figure 2. 2 21 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Property Profile Legend Planimetrics Survey 2 Contours Year- 2017 2 Ft Contours 10 Ft Contours 10 Ft Contours Environmental 3 Erosion Hazard Zone Review Buffer Environmental 1 Creek Centerlines 0 150 300 ft 7/22/2022 This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. It does not represent an on-the-ground survey. This product has been produced by the City of Austin for the sole purpose of geographic reference. No warranty is made by the City of Austin regarding specific accuracy or completeness. Common Sense. Teamwork. Expertise. WWW.CIVILTEAMENGINEERS.COMTBPE # F-21956GREAT HILLS LIFTSTATION SITEEROSIONHAZARD ZONEFIGURE 1SPICEBRUSH DRBULL CREEK22 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 60350700ftGREAT HILLS LIFT STATIONFIGURE 2Civil Team Engineers, LLCTexas Registered Engineering Firm F-21956NOT FOR CONSTRUCTIONTHIS DOCUMENT IS RELEASED FOR THE PURPOSEOF INTERIM REVIEW UNDER THE AUTHORITY OF:CESAR CALDERON JR, P.E.TEXAS NO:107183 ON DATE: 7/25/2022IT IS NOT TO BE USED FOR CONSTRUCTION, BIDDINGOR PERMIT PURPOSES.NOTES1. AVERAGE APPROXIMATE CHANNEL WIDTH: USING 2' CONTOUR MAP: 80'2. PROJECT STREAM REACH LENGTH: 800' (80' x 10)3. SINUOSITY, REFER TO FIGURE 3: 1.144. TOP WIDTHS (FT) (WEX): 34.4', 23.4', 49.5'5. CROSS SECTIONAL AREA AT CROSS SECTIONS (FT2): 60.2, 32.25, 74.356. EXISTING CHANNEL DEPTH (FT)(DEX) AT CROSS SECTIONS: 1.75', 1.37', 1.50'7. AVERAGE EXISTING CHANNEL DEPTH (FT)(DEX): 1.54'8. POTENTIAL FUTURE INCISION DEPTH (DI): 4.62' (1.54 x 3)9. EXISTING CONTOURS SHOWN IN THIS EXHIBIT ARE FROM THE CITY'S PROPERTY PROFILE SITE10. POTENTIAL FUTURE INCISED BED LEVEL AT PROPOSED LIFT STATION IS 634.38' AND SUBSURFACE EROSION HAZARD ZONE IS 633.38'.Common Sense. Teamwork. Expertise. WWW.CIVILTEAMENGINEERS.COMTBPE # F-21956DSSUS660650640630DS - DOWNSTREAM660650640630LS - LIFTSTATION670660650640US - UPSTREAM660650640630660650640630241'-8 1/4"34.4'147'-8 3/4"23.4'337'-1 3/4"49.5'LIFTSTATION SITEEX. LIFTSTATION SITEFUTURE INCISEDBED LEVELSUBSURFACE EROSIONHAZARD ZONE0204060-20-40-60-80-100-1200204060-20-40-60801000204060-20-40-6080100-80120140160639636.5EX. GROUND ELEV.SUBSURFACEEROSION HAZARDZONESPICEBRUSH DRBULL CREEK23 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Property Profile Legend Environmental 1 Creek Centerlines 0 350 700 ft 7/25/2022 This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. It does not represent an on-the-ground survey. This product has been produced by the City of Austin for the sole purpose of geographic reference. No warranty is made by the City of Austin regarding specific accuracy or completeness. SPICEBRUSH DRGREAT HILLS LIFTSTATION SITESTREAM LENGTH1,785'VALLEY LENGTH1,560'SINUOSITY MAPSINUOSITY = 1.14Common Sense. Teamwork. Expertise. WWW.CIVILTEAMENGINEERS.COMTBPE # F-21956UPSTREAMBOUNDARYAREASPICEBRUSH COVEFIGURE 324 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6GUPTA RANJIT B & ALKA BHANOT LOT 7 GREAT HILLS XXVI EXIST 2" PVC (SCH 40) WATER LINE NO CITY FLOW METER. LOCATION PROVIDED BY AUSTIN WATER (NOT SURVEYED). CONTRACTOR TO CONFIRM PRIOR TO EXCAVATION. NATURAL GAS METER TO BE INSTALLED BY TGS. CONTRACTOR TO COORDINATE WITH TGS FOR GAS LINE INSTALLATION AND SEQUENCING (DRESSER 5M METER REGULATED PRESSURE WITH CAPACITY OF 6,600 CFH @ 5 PSI) 667 PROPOSED 2" POLYETHYLENE GAS LINE. GAS LINE AND METER TO BE INSTALLED BY OTHERS EXIST 8" DI WWL 93-0626 666 EXIST 8" DI WWL 93-0626 EXIST 2" PVC (SCH 40) WATER LINE TO BE RELOCATED PRIOR TO WET WELL EXCAVATION G 665 EXIST 8" DI WWL 93-0626 CONTRACTOR TO INSTALL GASEOUS FUEL SYSTEM AT GENERATOR PAD 6 6 4 SEE DETAIL SHEET C24 CONTRACTOR TO INSTALL 2" CUT OFF VALVE ABOVE GROUND ADJACENT TO GENERATOR PROPOSED FENCE 663 662 PROPOSED NATURAL GAS GENERATOR PAD 21'-6” x 10'-0” 661 J 660 350KW NATURAL GAS GENERATOR BTU FUEL CONSUMPTION: PRESSURE: 4,328 FT3/HR 5-PSIG I PROPOSED NEW 5-FT DIA PRECAST POLYMER MANHOLE #1 PROPOSED 5/8" METER EXISTING WATER LINE TAP PROPOSED 2" RPZ BACKFLOW PREVENTION VALVE (SEE DETAIL ON SHEET C24) PROPOSED 2" PVC SCH 40 WATERLINE CONTRACTOR TO RELOCATE AND ADJUST HOSE BIB TO MATCH PROPOSED GRADE AND LOCATION SHOWN (SEE DETAIL ON SHEET C24). PROPOSED HOSE BIB TO BE ATTACHED AND SECURED TO BOLLARD PROPOSED 15" SDR-26 PVC WWL CONCRETE ELECTRICAL PAD TO BE REMOVED H EXIST FORCE MAIN TO BE ABANDONED IN PLACE (CUT & PLUG) EXIST 8" WWL TO BE ABANDONED IN PLACE PROPOSED 5-FT DIA PRECAST MANHOLE #2 BLAKELY DAVID LOT 6 GREAT HILLS XXVI EXIST 8" PVC WWL 84-0909 659 658 657 656 655 654 653 652 651 6 5 0 6 4 9 6 4 8 647 646 645 644 643 642 4 6416 641 640 1 639 638 100-YEAR FLOODPLAIN EXIST 8" PVC WWL 84-0909 JIB CRANE REACH PROPOSED FENCE A K L EXISTING WASTEWATER MANHOLE #21750 RIM ELEV.=656.60' FL 8" DI IN=646.67' (NW) FL 8" DI OUT=646.04' (SE) SWING GATES B T S PROPOSED JUNCTION BOX RACK 12-FT (ID) WET WELL INSTALL 79LF OF 2" POLYETHYLENE GAS LINE ON OWNER SIDE OF GAS METER PROPOSED 18" PS115 PVC WWL N EXIST 8" DI WWL TO BE ABANDONED BH1 M O JIB CRANE U W W W W BOLLARD EXIST 12" WWL TO BE ABANDONED IN PLACE PROPOSED VALVE VAULT HATCHES BH2 F PROPOSED CONCRETE RETAINING WALL EXIST 12" PVC WWL 84-0909 BH3 PROPOSED VALVE VAULT G P PROPOSED 4-FT DIA PRECAST MANHOLE #4 PROPOSED CONTROL ENCLOSURE C E 6 5 7 6 5 6 655 654 3 2 5 5 6 6 1 5 6 650 649 648 647 646 645 644 6 4 3 500-YR FEMA FLOODPLAIN / COA 100-YEAR FULLY DEVELOPED FLOODPLAIN R PROPOSED 16" CL-350 DI FM PROPOSED 12" SDR-26 PVC WWL 6 4 2 PROPOSED 12" SDR-26 PVC WWL Q PROPOSED 4-FT DIA PRECAST MANHOLE #3 INSTALL PROPOSED 6-FT DIA PRECAST VAULT WITH ULTRASONIC FLOW METER ON EXISTING FORCE MAIN. SEE DETAIL ON SHEET C24. CREEK ℄ REMOVE EXISTING FLOW METER VAULT. EXIST 16" DI FM 85-0594 500-YR FEMA FLOODPLAIN / COA 100-YEAR FULLY DEVELOPED FLOODPLAIN 6 4 1 EWING MANUELA & GREGORY R LOT 5 GREAT HILLS XXVI 640 639 6 3 8 0 VERTICAL SCALE IN FEET 10 20 HORIZONTAL SCALE IN FEET SCALE: 1" = 10' LEGEND PROPOSED CONCRETE PAVEMENT SITE DATA TABLE ALLOWED PROPOSED CHRISTOPHER M. LEAL TOTAL SITE AREA ZONING I I I I N N O O T T P P R R C C S S E E D D N N O O S S V V E E R R I I I I E E T T A A D D Y Y B B . . V V E E R R . . O O N N T E O F TE X A S A S T P R O F E 97373 D LICEN S E SSIONA L E N R G IN EE THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY CHRISTOPHER M. LEAL LIC. # 97373 I CERTIFY THAT THESE DRAWINGS ARE COMPLETE, ACCURATE AND ADEQUATE FOR PURPOSES, INCLUDING CONSTRUCTION, BUT ARE NOT AUTHORIZED FOR CONSTRUCTION UNTIL FORMAL CITY APPROVAL. INTENDED THEIR S A X E T , I N T S U A F O Y T C I R E T A W N T S U A I I I I I N O S V D S E C V R E S G N R E E N G N E I I I T U O Y A L E T S N O T A T S T F I L I NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY DRAWN BY DRAWN BY JRW 02/22 DESIGNED BY DESIGNED BY TJK 02/22 CHECKED BY CHECKED BY CML 02/22 REVIEWED BY REVIEWED BY S T N E M E V O R P M I I N O T A T S T F I L A E R A T S E W H T R O N 3 5 . I O N N O T A T S T F I L S L L I H T A E R G C10 1 E M A N T E E H S 2 E M A N T E E H S . B T S D S E _ A O C , - - - - , \ . I \ I G W D E T S - 0 6 7 0 \ S T E E H S N G D N G S E D _ S L _ S L L H _ T A E R G _ A O C _ 0 6 7 0 S T C E J O R P I \ \ : X : M P 8 0 4 4 2 0 2 / 3 1 / 3 N A M D E T S N E K 9009 1/2 SPICEBRUSH DRIVE AUSTIN, TX 78759 CASE NUMBER: SP-2022-0537C SHEET 18 OF 63 (TOTAL LOC)NEW PROPOSED 5/8" METEREXISITNG 2" WATER LINE TAPNEW PROPOSED 2" METER25 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 ENVIRONMENTAL COMMISSION RECOMMENDATION 20240306-005 Date: March 6, 2024 Subject: Northwest Area Lift Station Improvements Great Hills Lift Station No.53 (SP- 2022-0537C) Second by: Kevin Ramberg Motion by: Jennifer Bristol WHEREAS, the Environmental Commission understands the Austin Water Utility Department is requesting a Land Use Commission variance to allow development in the CWQZ for a lift station per LDC 25-8-261 and; A Land Use Commission variance is requested to allow construction of a building on a slope with a gradient of more than 25% per LDC 25-8-302(A)(1) and; A Land Use Commission variance is requested to allow fill up to 14 feet for construction of a lift station exceeding the 4-foot limitation per LDC 25-8-342 and; WHEREAS, the Environmental Commission recognizes the Land Use Commission variance is recommended by staff with a condition and; THEREFORE, the Environmental Commission recommends the three Land Use Commission variances with the following conditions: Staff Conditions: 1. Provide structural containment of the fill with a retaining wall. Environmental Commission Conditions: 1. Limit construction and removal of trees from March to August when the endangered Golden-cheeked Warbler is in the area. 2. Applicant will solicit and incorporate Watershed Protection Jollyville Plateau salamander expert review and comment on the temporary and permanent stormwater design. 3. After construction, the disturbed areas from both this construction and previous emergency repairs are restored using 609S species and that those areas are maintained and mowed to the minimum extent practical to maintain access to the lift stations by Austin Water staff. Vote: 7-0 For: Perry Bedford, Jennifer Bristol, Mariana Krueger, Colin Nickells, Haris Qureshi, Kevin Ramberg, and David Sullivan Against: None Abstain: Richard Brimer Absent: Hanna Cofer, Peter Einhorn, and Melinda Schiera 1 of 2 26 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 Attest: Kevin Ramberg, Environmental Commission Chair 2 of 2 27 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6ITEM FOR ENVIRONMENTAL COMMISSION AGENDA COMMISSION MEETING DATE: March 6, 2024 NAME & NUMBER OF PROJECT: NAME OF APPLICANT OR ORGANIZATION: Northwest Area Lift Station Improvements Great Hills Lift Station No.53 (SP-2022-0537C) Sharon Hamilton, Civil Team Engineers LLC on behalf of the Austin Water Utility Department LOCATION: 9009 ½ Spicebrush Drive, Austin, TX 78759 COUNCIL DISTRICT: District 6 ENVIRONMENTAL REVIEW STAFF: WATERSHED: REQUEST NO. 1: REQUEST NO. 2: REQUEST NO. 3: Brad Jackson, Environmental Compliance Specialist Senior, DSD, 512-974-2128, Brad.Jackson@austintexas.gov Bull Creek, Water Supply Suburban, Drinking Water Protection Zone A Land Use Commission variance is requested to allow development in the CWQZ for a lift station per LDC 25-8-261 A Land Use Commission variance is requested to allow construction of a building on a slope with a gradient of more than 25% per LDC 25-8-302(A)(1) A Land Use Commission variance is requested to allow fill up to 14 feet for construction of a lift station exceeding the 4-foot limitation per LDC 25-8-342 28 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 STAFF RECOMMENDATION NO. 1: STAFF RECOMMENDATION NO. 2: STAFF RECOMMENDATION NO. 3: Staff recommends approval of the variance with a condition Staff recommends approval of the variance with a condition Staff recommends approval of the variance with a condition STAFF CONDITION: Provide structural containment of the fill with a retaining wall. 29 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 Development Services Department Staff Recommendations Concerning Required Findings Project Name: Ordinance Standard: Watershed Protection Ordinance Variance Request: Northwest Area Lift Station Improvements To allow development in the CWQZ for a lift station per LDC 25-8-261 Include an explanation with each applicable finding of fact. A. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: 1. The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes. The variance will not be providing a special privilege to the applicant. The lift station is currently existing and in operation to provide wastewater (WW) service to the neighborhood. The variance for construction in the CWQZ will allow the replacement of the existing lift station with a new lift station to continue to provide WW service to the neighborhood. The old lift station will be decommissioned when the new lift station is complete. 2. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; Yes. The scale and layout of the new lift station has been designed based on the needs of the existing neighborhood for WW service. b) Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; Yes. The size and design of the new lift station will be the minimum amount of disturbance in the CWQZ to continue to supply WW service to the neighborhood and protect the creek from WW overflows due to equipment failure. c) Does not create a significant probability of harmful environmental consequences. 30 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 The variance does not create a significant probability of harmful consequences. Yes. The existing lift station is aging and prone to failure, leading to a WW overflow into Bull Creek. The variance will allow a new lift station and protect Bull Creek from a WW overflow. 3. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes. The project will provide for better water quality for the site and the neighborhood by preventing a failure of the existing lift station and WW overflow into Bull Creek. B. The Land Use Commission may grant a variance from a requirement of Section 25-8-422 (Water Supply Suburban Water Quality Transition Zone), Section 25-8-452 (Water Supply Rural Water Quality Transition Zone), Section 25-8-482 (Barton Springs Zone Water Quality Transition Zone), Section 25-8-368 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long), or Article 7, Division 1 ( Critical Water Quality Zone Restrictions ), after determining that:: 1. The criteria for granting a variance in Subsection (A) are met; Yes, see above. 2. 3. The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; Yes. The lift station must be constructed in line with the existing WW infrastructure which is also in the CWQZ. The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Yes. The lift station is designed to provide WW service to the existing neighborhood. Staff Determination: Staff determines that the findings of fact have been met. Staff recommends the following condition: Provide structural containment of the fill with a retaining wall. Environmental Reviewer (DSD) __________________________ Date 02/07/24 Environmental Review Manager (DSD) _____________________________ Mike McDougal Date 2/8/24 Deputy Environmental Officer (WPD) _____________________________ Liz Johnston Date 02/22/2024 31 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 Development Services Department Staff Recommendations Concerning Required Findings Project Name: Ordinance Standard: Watershed Protection Ordinance Variance Request: Northwest Area Lift Station Improvements To allow construction of a building on a slope with a gradient of more than 25% per LDC 25-8-302(A)(1) Include an explanation with each applicable finding of fact. A. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: 1. The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes. The variance will not be providing a special privilege to the applicant. The lift station is currently existing and in operation to provide WW service to the neighborhood. The variance for the building on slopes is required to house the equipment necessary for the lift station to operate. 2. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; Yes. The scale and layout of the new lift station and associated equipment housed within the building has been designed based on the needs of the existing neighborhood for WW service. b) Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; Yes. The building serves only to house equipment to protect it from the elements and ensure safe operation of the new lift station. The building is only 12 feet by 20 feet in size. c) Does not create a significant probability of harmful environmental consequences. The variance does not create a significant probability of harmful consequences. Yes. The existing lift station is aging and prone to failure, leading to a WW overflow into Bull 32 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 Creek. The variance will allow a new lift station and protect Bull Creek from a WW overflow. 3. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes. The project will provide for better water quality for the site and the neighborhood by preventing a failure of the existing lift station and WW overflow into Bull Creek. B. The Land Use Commission may grant a variance from a requirement of Section 25-8-422 (Water Supply Suburban Water Quality Transition Zone), Section 25-8-452 (Water Supply Rural Water Quality Transition Zone), Section 25-8-482 (Barton Springs Zone Water Quality Transition Zone), Section 25-8-368 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long), or Article 7, Division 1 ( Critical Water Quality Zone Restrictions ), after determining that:: 1. The criteria for granting a variance in Subsection (A) are met; 2. 3. Not Applicable Not Applicable Not Applicable The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Staff Determination: Staff determines that the findings of fact have been met. Staff recommends the following condition: Provide structural containment of the fill with a retaining wall. Environmental Reviewer (DSD) __________________________ Date 02/07/24 Environmental Review Manager (DSD) _____________________________ Mike McDougal Date 2/8/24 Deputy Environmental Officer (WPD) _____________________________ Liz Johnston Date 02/22/2024 33 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 Development Services Department Staff Recommendations Concerning Required Findings Project Name: Ordinance Standard: Watershed Protection Ordinance Variance Request: Northwest Area Lift Station Improvements To allow fill up to 14 feet for construction of a lift station exceeding the 4 foot limitation per LDC 25-8-342 Include an explanation with each applicable finding of fact. A. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: 1. The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes. The variance will not be providing a special privilege to the applicant. The lift station is currently existing and in operation to provide WW service to the neighborhood. The variance for fill up to 14’ will allow the replacement of the existing lift station with a new lift station to continue to provide WW service to the neighborhood. The old lift station will be decommissioned when the new lift station is complete. 2. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; Yes. The scale and layout of the new lift station has been designed based on the needs of the existing neighborhood for WW service. b) Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; Yes. The fill is the minimum deviation from the 4-foot limit to allow access to the new lift station for maintenance and emergency repairs. c) Does not create a significant probability of harmful environmental consequences. Yes. The variance does not create a significant probability of harmful consequences. The existing lift station is aging and prone to failure, leading to a WW overflow into Bull 34 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Page 2 of 2 Creek. The variance will allow a new lift station and protect Bull Creek from a WW overflow. 3. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes. The project will provide for better water quality for the site and the neighborhood by preventing a failure of the existing lift station and WW overflow into Bull Creek. B. The Land Use Commission may grant a variance from a requirement of Section 25-8-422 (Water Supply Suburban Water Quality Transition Zone), Section 25-8-452 (Water Supply Rural Water Quality Transition Zone), Section 25-8-482 (Barton Springs Zone Water Quality Transition Zone), Section 25-8-368 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long), or Article 7, Division 1 ( Critical Water Quality Zone Restrictions ), after determining that:: 1. The criteria for granting a variance in Subsection (A) are met; 2. 3. Not Applicable Not Applicable Not Applicable The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Staff Determination: Staff determines that the findings of fact have been met. Staff recommends the following condition: Provide structural containment of the fill with a retaining wall. Environmental Reviewer (DSD) __________________________ Date 02/07/24 Environmental Review Manager (DSD) _____________________________ Mike McDougal Date 2/8/24 Deputy Environmental Officer (WPD) _____________________________ Liz Johnston Date 02/22/2024 35 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Northwest Li(cid:12) Sta(cid:15)on Improvements, Great Hills Li(cid:12) Sta(cid:15)on SP-2022-0537C Variance Request Ar(cid:15)cle 7, Division 1, Cri(cid:15)cal Water Quality Zone Restric(cid:15)ons, 25-8-261 Land Use Commission variance determina(cid:17)ons from 25-8-41(A) of the City Code 1. The requirement will deprive the applicant of a privilege or the safety of property given to owners of other similarly situated proper(cid:17)es with approximately contemporaneous development; a. YES, The exis(cid:17)ng li, sta(cid:17)on was approved with the subdivision and is noted on the Subdivision plat included on sheet 7 of the plans, dated March 1993. Replacement of the li, sta(cid:17)on is required to con(cid:17)nue provision of safe wastewater service to the subdivision. Therefore denying the variance will deprive the en(cid:17)re subdivision of wastewater service. 2. The variance a. Is not based on a condi(cid:17)on caused by the method chosen by the applicant to develop the property, unless the development method provides greater overall environmental protec(cid:17)on than is achievable without the variance. i. YES, The exis(cid:17)ng li, sta(cid:17)on is failing and must be upgraded; Aus(cid:17)n Water has an exis(cid:17)ng system that collects at this li, sta(cid:17)on. In order to con(cid:17)nue providing wastewater service to the subdivision and keep the exis(cid:17)ng li, sta(cid:17)on running during construc(cid:17)on, a new li, sta(cid:17)on must be built immediately adjacent to the exis(cid:17)ng. Denying the variance will deprive the en(cid:17)re subdivision of wastewater service. b. Is the minimum change necessary to avoid the depriva(cid:17)on of a privilege given to other property owners and to allow a reasonable use of the property i. YES, The li, sta(cid:17)on must be built at the exis(cid:17)ng collec(cid:17)on point in order to avoid rebuilding the en(cid:17)re wastewater infrastructure of the subdivision. Denying the variance will deprive the en(cid:17)re subdivision of wastewater service. c. Does not create a signiﬁcant probability of harmful environmental consequences, and i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing, leaving the poten(cid:17)al for wastewater spills into Bull Creek if it is not replaced. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. d. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing, leaving the poten(cid:17)al for wastewater spills into Bull Creek if it is not replaced. The new li, sta(cid:17)on will 36 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. Addi(cid:17)onal Land Use Commission variance determina(cid:17)ons for a requirement of Ar(cid:17)cle 7, Division 1 (Cri(cid:17)cal Water Quality Zone Restric(cid:17)ons: e. The criteria for gran(cid:17)ng a variance in Subsec(cid:17)on A are met: i. YES, see above for each criteria. f. The requirement for which a variance is requested prevents a reasonable, economic use of the en(cid:17)re property; i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. g. The variance is the minimum devia(cid:17)on from the code requirement necessary to allow a reasonable economic use of the en(cid:17)re property. i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. 37 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Northwest Li(cid:12) Sta(cid:15)on Improvements, Great Hills Li(cid:12) Sta(cid:15)on SP-2022-0537C Variance Request Ar(cid:15)cle 7, Division 3, Construc(cid:15)on of a Building or Parking Area, 25-8-302(A)(1) Land Use Commission variance determina(cid:17)ons from 25-8-41(A) of the City Code 1. The requirement will deprive the applicant of a privilege or the safety of property given to owners of other similarly situated proper(cid:17)es with approximately contemporaneous development; 2. The variance a. YES, The exis(cid:17)ng li, sta(cid:17)on was approved with the subdivision and is noted on the Subdivision plat included on sheet 7 of the plans, dated March 1993. Replacement of the li, sta(cid:17)on is required to con(cid:17)nue provision of safe wastewater service to the subdivision. Therefore denying the variance will deprive the en(cid:17)re subdivision of wastewater service. The proposed building is a simple electrical enclosure sized 12’x20’ to house and protect necessary instrumenta(cid:17)on and controls for the improved li, sta(cid:17)on. Sheets 49 and 60 provide detailed informa(cid:17)on on the enclosure/building. The building is not proposed as a habitable structure and no staﬀ will be working daily at the structure – maintenance crews will only access the sta(cid:17)on periodically for opera(cid:17)ons and maintenance. a. Is not based on a condi(cid:17)on caused by the method chosen by the applicant to develop the property, unless the development method provides greater overall environmental protec(cid:17)on than is achievable without the variance. i. YES, The exis(cid:17)ng li, sta(cid:17)on is failing and must be upgraded; Aus(cid:17)n Water has an exis(cid:17)ng system that collects at this li, sta(cid:17)on. In order to con(cid:17)nue providing wastewater service to the subdivision and keep the exis(cid:17)ng li, sta(cid:17)on running during construc(cid:17)on, a new li, sta(cid:17)on must be built immediately adjacent to the exis(cid:17)ng. Denying the variance will deprive the en(cid:17)re subdivision of wastewater service or will require the aging and deteriorated li, sta(cid:17)on to remain in service. b. Is the minimum change necessary to avoid the depriva(cid:17)on of a privilege given to other property owners and to allow a reasonable use of the property i. YES, The li, sta(cid:17)on must be built at the exis(cid:17)ng collec(cid:17)on point in order to avoid rebuilding the en(cid:17)re wastewater infrastructure of the subdivision. Denying the variance will deprive the en(cid:17)re subdivision of wastewater service or will require the aging and deteriorated li, sta(cid:17)on to remain in service. c. Does not create a signiﬁcant probability of harmful environmental consequences, and i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing, leaving the poten(cid:17)al for wastewater spills into Bull Creek if it is not replaced. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to 38 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6the subdivision. Denying the variance will require the aging and deteriorated li, sta(cid:17)on to remain in service. d. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing, leaving the poten(cid:17)al for wastewater spills into Bull Creek if it is not replaced. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. Addi(cid:17)onal Land Use Commission variance determina(cid:17)ons for a requirement of Ar(cid:17)cle 7, Division 1 (Cri(cid:17)cal Water Quality Zone Restric(cid:17)ons: e. The criteria for gran(cid:17)ng a variance in Subsec(cid:17)on A are met: i. YES, see above for each criteria. f. The requirement for which a variance is requested prevents a reasonable, economic use of the en(cid:17)re property; i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing. The new li, sta(cid:17)on will provide improved service and reliability including emergency generator and improved access for maintenance and will allow for con(cid:17)nued service to the subdivision. g. The variance is the minimum devia(cid:17)on from the code requirement necessary to allow a reasonable economic use of the en(cid:17)re property. i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. 39 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6Northwest Li(cid:12) Sta(cid:15)on Improvements, Great Hills Li(cid:12) Sta(cid:15)on SP-2022-0537C Variance Request Ar(cid:15)cle 7, Division 5, Fill Requirements 25-8-342 Land Use Commission variance determina(cid:17)ons from 25-8-41(A) of the City Code 1. The requirement will deprive the applicant of a privilege or the safety of property given to owners of other similarly situated proper(cid:17)es with approximately contemporaneous development; a. YES, The exis(cid:17)ng li, sta(cid:17)on was approved with the subdivision and is noted on the Subdivision plat included on sheet 7 of the plans, dated March 1993. Replacement of the li, sta(cid:17)on is required to con(cid:17)nue provision of safe wastewater service to the subdivision. Therefore denying the variance will deprive the en(cid:17)re subdivision of wastewater service. The proposed li, sta(cid:17)on is immediately adjacent to the exis(cid:17)ng. In order to provide maintenance access to the new li, sta(cid:17)on, ﬁll of 4 feet up to 13.5 feet is required, as shown on sheet 22 of the plans. 2. The variance a. Is not based on a condi(cid:17)on caused by the method chosen by the applicant to develop the property, unless the development method provides greater overall environmental protec(cid:17)on than is achievable without the variance. i. YES, The exis(cid:17)ng li, sta(cid:17)on is failing and must be upgraded; Aus(cid:17)n Water has an exis(cid:17)ng system that collects at this li, sta(cid:17)on. In order to con(cid:17)nue providing wastewater service to the subdivision and keep the exis(cid:17)ng li, sta(cid:17)on running during construc(cid:17)on, a new li, sta(cid:17)on must be built immediately adjacent to the exis(cid:17)ng. Denying the variance will deprive the en(cid:17)re subdivision of wastewater service. The proposed design provides accessible facili(cid:17)es for Aus(cid:17)n Water to perform con(cid:17)nued maintenance and opera(cid:17)ons. b. Is the minimum change necessary to avoid the depriva(cid:17)on of a privilege given to other property owners and to allow a reasonable use of the property i. YES, The li, sta(cid:17)on must be built at the exis(cid:17)ng collec(cid:17)on point in order to avoid rebuilding the en(cid:17)re wastewater infrastructure of the subdivision. Denying the variance will deprive the en(cid:17)re subdivision of wastewater service. Fill must be added to level up the site and make the facility accessible by vehicles in emergency situa(cid:17)ons. c. Does not create a signiﬁcant probability of harmful environmental consequences, and i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing, leaving the poten(cid:17)al for wastewater spills into Bull Creek if it is not replaced. The new li, sta(cid:17)on will provide improved service and reliable access for Aus(cid:17)n Water, as well as allowing for con(cid:17)nued service to the subdivision. 40 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6d. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance i. YES, the exis(cid:17)ng li, sta(cid:17)on is aging and failing, leaving the poten(cid:17)al for wastewater spills into Bull Creek if it is not replaced. The new li, sta(cid:17)on will provide improved service and reliability and will allow for con(cid:17)nued service to the subdivision. 41 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6LOT 7 GREAT HILLS XXVI BOOK 91 PAGE 295 P.R.T.C.TX. LOT 6 GREAT HILLS XXVI BOOK 91 PAGE 295 P.R.T.C.TX. LOT 5 GREAT HILLS XXVI BOOK 91 PAGE 295 P.R.T.C.TX. P.R.T.C.TX. ABANDONED ACCESS ROAD EASEMENT WATER QUALITY TRANSITION ZONE CRITICAL WATER QUALITY ZONE 30' W.W.E. BOOK 91 PAGE 295 P.R.T.C.TX. EXIST 8" DI WWL 93-0626 EXIST 8" DI WWL 93-0626 WW WW W W WW WW W W M H EXIST 8" DI WWL 93-0626 150-FT ZONE FOR CRITICAL ENVIRONMENTAL FEATURE W W M H W W APPROXIMATE LOCATION OF 10' ELECTRIC, TELEPHONE & TV CABLE EASEMENT VOLUME 11642, PAGE 268 P.R.T.C.TX. W W CRITICAL ENVIRONMENTAL FEATURE CANYON RIMROCK W W W W M H COA WASTEWATER EASEMENT PARCEL 5354.01 WE 0.042 ACRES (1,846 S.F.) W W COA WASTEWATER EASEMENT PARCEL 5354.02 WE 0.091 ACRES (3,965 S.F.) M H W W W W PROPOSED LIFT STATION 100-YR FEMA FLOODPLAIN / COA 25-YEAR FULLY DEVELOPED FLOODPLAIN W W 500-YR FEMA FLOODPLAIN / COA 100-YEAR FULLY DEVELOPED FLOODPLAIN WASTE WATER EASEMENT BOOK 91 PAGE 295 P.R.T.C.TX. EXIST 12" PVC WWL 84-0909 ℄ BULL CREEK W W WW WW WW WW WW WW WW WW W W M H W W M H EXISTING LIFT STATION (TO BE DEMOLISHED) W W M H W W W W M H W W W W M H EXIST 8" PVC WWL 84-0909 EXIST 8" PVC WWL 84-0909 EXIST 16" DI FM 85-0594 SUBSURFACE EROSION HAZARD ZONE P.U.E. DRAINAGE EASEMENT & PRIVATE GREENBELT 500-YR FEMA FLOODPLAIN / COA 100-YEAR FULLY DEVELOPED FLOODPLAIN CRITICAL ENVIRONMENTAL FEATURE CANYON RIMROCK 100-YR FEMA FLOODPLAIN / COA 25-YEAR FULLY DEVELOPED FLOODPLAIN I I I I N N O O T T P P R R C C S S E E D D N N O O S S V V E E R R I I I I E E T T A A D D Y Y B B 0 VERTICAL SCALE IN FEET 20 40 HORIZONTAL SCALE IN FEET SCALE: 1" = 20' LEGEND CRITICAL WATER QUALITY ZONE WATER QUALITY TRANSITION ZONE . . V V E E R R . . O O N N T E O F TE X A S A S T CHRISTOPHER M. LEAL P R O F E 97373 D LICEN S E SSIONA L E N R G IN EE 1/4/2024 THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY CHRISTOPHER M. LEAL LIC. # 97373 I CERTIFY THAT THESE DRAWINGS ARE COMPLETE, ACCURATE AND ADEQUATE FOR PURPOSES, INCLUDING CONSTRUCTION, BUT ARE NOT AUTHORIZED FOR CONSTRUCTION UNTIL FORMAL CITY APPROVAL. INTENDED THEIR S A X E T , I N T S U A F O Y T C I R E T A W N T S U A I I I I I N O S V D S E C V R E S G N R E E N G N E I I S T N E M E V O R P M I I N O T A T S T F I L A E R A T S E W H T R O N 3 5 . I O N N O T A T S T F I L S L L I H T A E R G S E R U T A E F L A T N E M N O R V N E I NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY DRAWN BY DRAWN BY JRW 02/22 DESIGNED BY DESIGNED BY TJK 02/22 CHECKED BY CHECKED BY CML 02/22 REVIEWED BY REVIEWED BY 1120 S. Capital of Texas Highway CityView 2, Suite 100 Austin, Texas 78746 P - 512.338.1704 F - 512.338.1784 TBPE Firm #6535 www.kfriese.com C2 1 E M A N T E E H S 2 E M A N T E E H S . B T S D S E _ A O C , - - - - , . \ \ \ I G W D R V N E - 0 6 7 0 S T E E H S N G D N G S E D _ S L _ S L L I H _ T A E R G _ A O C _ 0 6 7 0 \ S T C E J O R P \ : X M P 1 5 : 4 4 2 0 2 4 1 / / G I L L I W Y D U J 150-FT ZONE FOR CRITICAL ENVIRONMENTAL FEATURE 9009 1/2 SPICEBRUSH DRIVE AUSTIN, TX 78759 CASE NUMBER: SP-2022-0537C SHEET 10 OF 63 CWQZWQTZNorthwest Area Lift Station Improvements Great Hills LiftStation No. 53 (SP-2022-0537C)_________________________________________________42 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6EXIST 8" DI WWL 93-0626 EXIST 8" DI WWL 93-0626 EXIST 8" DI WWL 93-0626 PROPOSED NATURAL GAS GENERATOR PAD E.O.S. 657.68 X PROPOSED WET WELL PROPOSED JUNCTION BOX RACK E.O.S. 657.68 X E.O.S. 657.38 X 1.0% X T.O.S. 657.5 T.O.S. 657.5 X 657 E.O.S. 656.48 X 2 . 0 % X T.O.C. 658.0 658 X T.O.S. 657.715 1 . 0 T.O.S. 657.715 X 2 2 . . 0 0 % % X T.O.W. 657.0 PROPOSED 5-FT DIA PRECAST POLYMER MH #1 657 PROPOSED CONTROL ENCLOSURE 2 . 0 % X T.O.C. 658.0 T.O.C. 658.0 X PROPOSED JIB CRANE PROPOSED VALVE VAULT X T.O.W. 656.3 2 . 0 % T.O.C. 658.0 X X T.O.C. 658.0 2 . 0 % T.O.W. 656.82 X T.O.W. 656.32 X EXIST 12" PVC WWL 84-0909 T.O.W. 656.23X X T.O.W. 656.0 PROPOSED 4-FT DIA PRECAST MH #4 6 4 8 6 4 7 6 4 6 6 4 5 PROPOSED 5-FT DIA PRECAST MH #2 500-YR FEMA FLOODPLAIN / COA 100-YEAR FULLY DEVELOPED FLOODPLAIN BLAKELY DAVID LOT 6 GREAT HILLS XXVI EXIST 8" PVC WWL 84-0909 EXIST 8" PVC WWL 84-0909 PROPOSED 4-FT DIA PRECAST MH #3 CREEK ℄ INSTALL PROPOSED 6-FT DIA CAST IN PLACE VAULT WITH ULTRASONIC FLOW METER ON EXISTING FORCE MAIN. SEE DETAIL ON SHEET C24. REMOVE EXISTING FLOW METER VAULT. EXIST 16" DI FM 85-0594 500-YR FEMA FLOODPLAIN / COA 100-YEAR FULLY DEVELOPED FLOODPLAIN EWING MANUELA & GREGORY R LOT 5 GREAT HILLS XXVI 0 VERTICAL SCALE IN FEET 10 20 HORIZONTAL SCALE IN FEET SCALE: 1" = 10' LEGEND x SPOT ELEVATIONS NATIVE GRASS SHALL BE INSTALLED PER SPEC SS02800 NOTE: 1. SEE STRUCTURAL SITE PLAN S1 SHEET FOR FINISH LIFT STATION ELEVATIONS AND TOP OF WALL SPOT ELEVATIONS. 2. PROPOSED CONCRETE PAVING TO MATCH PRE-EXISTING CONDITIONS. Slopes Table Number Minimum Slope Maximum Slope Color 1 2 3 4 0% 15% 25% 15% 25% 35% 35% AND GREATER 1817903% 35% 35% AND GREATER I I I I N N O O T T P P R R C C S S E E D D N N O O S S V V E E R R I I I I E E T T A A D D Y Y B B . . V V E E R R . . O O N N T E O F TE X A S A S T CHRISTOPHER M. LEAL P R O F E 97373 LICEN S E SSIONA L D E N R G IN EE 10/31/2022 THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY CHRISTOPHER M. LEAL LIC. # 97373 I CERTIFY THAT THESE DRAWINGS ARE COMPLETE, ACCURATE AND ADEQUATE FOR PURPOSES, INCLUDING CONSTRUCTION, BUT ARE NOT AUTHORIZED FOR CONSTRUCTION UNTIL FORMAL CITY APPROVAL. INTENDED THEIR S A X E T , I N T S U A F O Y T C I R E T A W N T S U A I I I I I N O S V D S E C V R E S G N R E E N G N E I I I N A L P G N D A R G N O T A T S T F I L I NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY DRAWN BY DRAWN BY JRW 02/22 DESIGNED BY DESIGNED BY TJK 02/22 CHECKED BY CHECKED BY CML 02/22 REVIEWED BY REVIEWED BY : S T N E M E V O R P M I I N O T A T S T F I L A E R A T S E W H T R O N 3 5 . I O N N O T A T S T F I L S L L I H T A E R G C13 1 E M A N T E E H S 2 E M A N T E E H S . B T S D S E _ A O C , - - - - , . \ \ I G W D D A R G - 0 6 7 0 \ S T E E H S N G D N G S E D _ S L _ S L L I H _ T A E R G _ A O C _ 0 6 7 0 \ S T C E J O R P \ : X M P 9 4 : 5 3 2 0 2 6 / / 1 1 N A M D E T S N E K 9009 1/2 SPICEBRUSH DRIVE AUSTIN, TX 78759 CASE NUMBER: SP-2022-0537C SHEET 21 OF 63 12' x 20' equipmentenclosure building onslopesNorthwest Area Lift Station Improvements Great Hills LiftStation No. 53 (SP-2022-0537C)_________________________________________________43 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6WW WW WW WW WW WW WW WW EXIST 8" DI WWL 93-0626 WW WW WW WW WW WW WW WW W W M W W H WW WW W W W W W W W W W W W W W W W W EXIST 8" DI WWL 93-0626 W W M H W W W W W W W W W W W W W W W W 0 VERTICAL SCALE IN FEET 10 20 HORIZONTAL SCALE IN FEET SCALE: 1" = 10' CUT/FILL TABLE NO. MIN. ELEVATION MAX. ELEVATION QTY 1 2 3 4 0.00 4.00 8.00 12.00 4.00 8.00 12.00 13.50 657 2 . 0 % 2 . 0 % 656 655 654 653 652 651 650 649 648 647 646 6 5 7 645 644 643 642 641 WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW WW EXIST 12" PVC WWL 84-0909 EXIST 8" DI WWL 93-0626 W W W W W W W W W W W W W W W W 2 . 0 % 6 5 8 2 2 . . 0 0 % % 657 W W W W 1 .0 W W W W W W M H W W W W W W W W W W M H 2 . 0 % W W M H 6 5 5 5 3 5 6 5 6 6 4 2 6 1.0% 1 5 5 6 0 6 9 4 648 647 646 645 644 643 W W W W W W W W W W W W W W W W W W W W W W W W W W M H 6 4 8 6 4 7 6 4 6 6 4 5 EXIST 16" DI FM 85-0594 EXIST 8" PVC WWL 84-0909 W W W W W W W W W W W W W W M H EXIST 8" PVC WWL 84-0909 WW WW WW WW WW WW WW I I I I N N O O T T P P R R C C S S E E D D N N O O S S V V E E R R I I I I E E T T A A D D Y Y B B . . V V E E R R . . O O N N T E O F TE X A S A S T CHRISTOPHER M. LEAL P R O F E 97373 D LICEN S E SSIONA L E N R G IN EE 1/4/2024 THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY CHRISTOPHER M. LEAL LIC. # 97373 I CERTIFY THAT THESE DRAWINGS ARE COMPLETE, ACCURATE AND ADEQUATE FOR PURPOSES, INCLUDING CONSTRUCTION, BUT ARE NOT AUTHORIZED FOR CONSTRUCTION UNTIL FORMAL CITY APPROVAL. INTENDED THEIR S A X E T , I N T S U A F O Y T C I R E T A W N T S U A I I I I I N O S V D S E C V R E S G N R E E N G N E I I : S T N E M E V O R P M I I I N O T A T S T F L A E R A T S E W H T R O N 3 5 . I O N N O T A T S T F L S L L H T A E R G I I I N A L P L L F D N A T U C N O T A T S T F L I I NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY DRAWN BY DRAWN BY JRW 02/22 DESIGNED BY DESIGNED BY TJK 02/22 CHECKED BY CHECKED BY CML 02/22 REVIEWED BY REVIEWED BY 1120 S. Capital of Texas Highway CityView 2, Suite 100 Austin, Texas 78746 P - 512.338.1704 F - 512.338.1784 TBPE Firm #6535 www.kfriese.com C14 1 E M A N T E E H S 2 E M A N T E E H S . B T S D S E _ A O C , E P A C S D N A L _ 4 3 X 2 2 _ A O C , \ \ \ . I G W D D A R G - 0 6 7 0 S T E E H S N G D N G S E D _ S L _ S L L H _ T A E R G _ A O C _ 0 6 7 0 S T C E J O R P I \ \ : X M P 4 1 : 5 4 2 0 2 / 4 / 1 I I G L L W Y D U J 9009 1/2 SPICEBRUSH DRIVE AUSTIN, TX 78759 CASE NUMBER: SP-2022-0537C SHEET 22 OF 63 Northwest Area Lift Station Improvements Great Hills LiftStation No. 53 (SP-2022-0537C)_________________________________________________44 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6 48"X96" ALUMINUM COVER WITH SAFETY GRATE PROVIDED BY WET WELL MANUFACTURER. (SEE NOTE 1) 6" 316 STAINLESS STEEL SCH. 40 GOOSENECK VENT WITH STAINLESS STEEL SCREEN 82"x65" EAST JORDAN, OR APPROVED EQUAL ALUMINUM FLOOR HATCH (SEE NOTE 1) 0 4 8 12 GRAPHIC SCALE: 1/4" = 1'-0" 36"x42" EAST JORDAN, OR APPROVED EQUAL ALUMINUM FLOOR HATCH (SEE NOTE 1) ACCESS LADDER (NOTE 2) TOS ELEV. 658.00 PROPOSED GRADE ELEV. 657.00 8" SURGE RELIEF PIPE, FL x PE, PVC SCH 80 16" DI., FL x MJ M N X AB O P LINK SEAL (TYP.) W L T I K H FL ELEV.649.42 FLOOR 647.50 SLOPE FLOOR TO DRAIN @ 2% SLOPE PIPE SUPPORT (TYP.) (SEE DETAIL SHEET C24) NOTE: 1. 2. ALL HATCHES TO BE INSTALLED WITH SAFETY GRATES. ACCESS LADDER TO BE INSTALLED WITH HALLIDAY MODEL L1E LADDER EXTENSION OR SIMILAR. 12' DIA WET WELL (SEE STRUCTURAL SHEETS) 12' - 0" I.D. 10" DISCHARGE 649.67 TOS EL. 658.00 6" STILLING WELL STAINLESS STEEL LIFTING CHAIN STAINLESS STEEL GUIDE RAIL 4" FLAP VALVE 3 PLY EPDM 1.5" ID AIR HOSE HOSE (TYP OF 3) 18" TEE, PVC TRANSITION COUPLING FROM GRAVITY LINE TO SCH 80 PVC 18" INFLUENT PIPE 627.69 HIGH LEVEL ALARM 626.69 LAG BACKUP 626.19 LEAD BACKUP 625.69 PUMP ON (LAG) 625.19 PUMP ON (LEAD) 624.69 18" SCH. 80 PVC DROP PIPE VERTICAL PIPE SUPPORTS AT 8' INTERVALS (SEE NOTE 15 ON SHEET C11) 8" TEE, PVC SCH 80 AC V AD Z F Q G R 2" PVC SCH 80 CAV PIPE 3 PLY EPDM 1.5" ID AIR HOSE HOSE 8" PVC SCH 80 SURGE RELIEF DROP PIPE PIPE SUPPORT (TYP.) (SEE DETAIL SHEET C24) 10" DISCHARGE PIPE FL x FL. DI. PUMP OFF 606.96 LOW LEVEL ALARM 605.96 AE SLOPE AT 1:1 (V:H) PIPE SUPPORT (SEE DETAIL SHEET C24) SUCTION HEAD 600.41 WET WELL BOTTOM 599.74 B ' 1 A D AF 1 1 PIPE SUPPORT (SEE DETAIL SHEET C24) I N M " 5 . 1 " 3 C WET WELL WIZARD (TYP OF 3) 1 LIFT STATION MECHANICAL SECTION 1/4" = 1' - 0" FULL SIZE I I I I N N O O T T P P R R C C S S E E D D N N O O S S V V E E R R I I I I E E T T A A D D Y Y B B . . V V E E R R . . O O N N T E O F TE X A S A S T CHRISTOPHER M. LEAL P R O F E 97373 LICEN S E SSIONA L D E N R G IN EE 10/31/2022 THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY CHRISTOPHER M. LEAL LIC. # 97373 I CERTIFY THAT THESE DRAWINGS ARE COMPLETE, ACCURATE AND ADEQUATE FOR PURPOSES, INCLUDING CONSTRUCTION, BUT ARE NOT AUTHORIZED FOR CONSTRUCTION UNTIL FORMAL CITY APPROVAL. INTENDED THEIR S A X E T , I N T S U A F O Y T C I R E T A W N T S U A I I I I I N O S V D S E C V R E S G N R E E N G N E I I S T N E M E V O R P M I I I N O T A T S T F L A E R A T S E W H T R O N 3 5 . I O N N O T A T S T F L S L L H T A E R G I I I I N O T C E S L A C N A H C E M N O T A T S T F L I I NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY DRAWN BY DRAWN BY JRW 02/22 DESIGNED BY DESIGNED BY TJK 02/22 CHECKED BY CHECKED BY CML 02/22 REVIEWED BY REVIEWED BY 1 E M A N T E E H S 2 E M A N T E E H S . B T S D S E _ A O C , - - - - , I \ \ . G W D H C E M - 0 6 7 0 \ S T E E H S N G D N G S E D _ S L _ S L L H _ T A E R G _ A O C _ 0 6 7 0 S T C E J O R P \ I \ : X M P 8 4 : 5 3 2 0 2 / 6 / 1 1 N A M D E T S N E K 9009 1/2 SPICEBRUSH DRIVE AUSTIN, TX 78759 CASE NUMBER: SP-2022-0537C SHEET 20 OF 63 C12 45 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6TO WET WELL & GENERATOR. SEE SHEET E2 FOR CONTINUATION. GENERAL NOTES: 1. ALL STUB-UP TRANSITIONS FROM DUCTBANKS TO ABOVE GRADE SHALL BE PVC COATED RIGID STEEL PLASTI-BOND, PERMA-COTE, REDH2OT, AS MANUFACTURED BY ROBROY OR REINFORCED THERMOSETTING RESIN CONDUIT AS LISTED IN AWU SPECIFICATIONS 2. MINIMUM DUCTBANK CONDUIT SHALL BE 1". 3. PROVIDE CAPPED WALL PENETRATION ABOVE CRYSTAL BALL FOR FUTURE ANTENNA ROUTING. 4. DUCTBANKS SHALL BE RUN UNDER THE SLAB FROM FIELD DEVICES TO DESIGNATED EQUIPMENT LOCATIONS IN THE ELECTRICAL EQUIPMENT ENCLOSURE. 5. CONDUIT ROUTING SHOWN IS USED FOR CLARIFICATION PURPOSES ONLY. MAINTAIN 3-90 DEGREE BENDS FOR ALL CONDUIT RUNS. EXCEEDING THIS NUMBER OF BENDS SHALL REQUIRE INSTALLING HANDHOLES. 6. REFER TO CITY OF AUSTIN LIFT STATION SPECIFICATIONS, FOR ADDITIONAL INFORMATION ON EQUIPMENT & INSTALLATION REQUIREMENTS. 7. ALL CONDUIT ROUTED WITHIN BUILDING SHALL BE EXPOSED. 8. ALL CONDUIT STUB-UPS IN MCC AND CONTROL PANEL SECTION SHALL BE FILLED WITH POLYWATER FST-250. 9. ALL ELECTRICAL DUCTBANK STEEL SHALL BE TIED INTO STRUCTURAL STEEL. BUBBLER CONTROL PANEL 12 11 2 AE METER INCOMING MAIN MISC. BREAKERS LOW VOLTAGE P1 STARTER P2 STARTER CONTROL PANEL FIT PUMP CONTROLS LSP2 RVAT LSP1 RVAT FIT CB 4 POWER & GROUNDING PLAN 1 SCALE: 1/2" = 1'-0" 13 3 1 SERVICE SPD 'SPD1' PQM 3P-600A MCB SPACE PANEL LP 120/240V 42CKT PANELBOARD XFMR T1 480V- 120/240V 1∅ 2P-30A PB 2P-60A SB SPACE PANEL LP SPD 'SPD2' 3P-20A 3P-20A SPACE SPACE A MCC ELEVATION SCALE: 1/4" = 1'-0" TO WET WELL & GENERATOR. SEE SHEET E2 FOR CONTINUATION. S LP-8,10 LP-4,6 21 LP-19 LP-15 LP-9 BUBBLER CONTROL PANEL 10 LP-9 TS A A A AE METER AE METER 16 LP-7 INCOMING MAIN MISC. BREAKERS LOW VOLTAGE P1 STARTER P2 STARTER CONTROL PANEL LP-20 LP-22 LP-19 LP-21,23 FIT GEN-ANN LSP1-C LSP2-C I-1 6 7 8 INCOMING MAIN MISC. BREAKERS LOW VOLTAGE P1 STARTER P2 STARTER CONTROL PANEL SPD LIGHTING & RECEPTACLE PLAN 2 SCALE: 1/2" = 1'-0" INSTRUMENTATION PLAN 3 SCALE: 1/2" = 1'-0" NOT FOR CONSTRUCTION KEYNOTES: INSTALL #250 MCM GROUND LOOP 2'-6" BELOW GRADE AND 2'-0" AWAY FROM BLDG. FOUNDATION. #3/0 BARE CU. BOND TO GROUND LUG IN SERVICE DISCONNECT. #2/0 BARE COPPER GROUND. BOND TO FOUNDATION AND BUILDING STEEL. TYPICAL 4 PLACES. #3/0 BARE CU. GROUND. BOND TO MCC GROUND BUS AT EACH END. INSTALL BUBBLER TUBING EXPOSED ON WALL INSIDE BLDG. PROVIDE SCH. 80 PVC STUB-UP THROUGH FLOOR FOR SLEEVE. 1PR. #16T/S, 3/4"C FOR WETWELL LEVEL. 2#14, 3/4"C. BUBBLER SOLENOID VALVE. 2#14, 3/4"C. BUBBLER LOW PRESSURE ALARM. 3PR. OUTDOOR TELEPHONE CABLE, 1"C. DEDICATED CIRCUIT FOR AIR COMPRESSOR AND AUTOMATIC DRAIN VALVE.. 3 TON HEAT PUMP. FAN COIL UNIT. 13 CADWELD CONNECTION. SEE DETAIL, SHEET E12. ALARM BEACON AND HORN. INSTALL 8'-0" ABOVE GRADE. ALL CONDUITS ENTERING MCC, SERVICE DISCONNECT AND ATS FROM BELOW GRADE SHALL BE FILLED W/POLYWATER FST-250. SURFACE MOUNT LED FIXTURE. LIGHONIA FEM L24 SERIES, 4000LM M,D 120 40k 80CRI, OR APPROVED EQUAL. 4G/5G COMMUNICATION CONTROL PANEL. MOUNT ON WALL. PROVIDE SINGLE WALL PENETRATION FOR 2 SETS OF COAX CABLE. 19 MOUNT 5G ANTENNAS TO BUILDING ROOF USING UNISTRUT SUPPORT. PROVIDE COAX CABLE SUPPORT, FROM WALL PENETRATION TO ANTENNAS, EVERY 5-'0". 3/4"C: 2#14(P), #12(G) LED EMERGENCY EGRESS FIXTURE. LITHONIA ECRG RDM6. 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 20 21 TO WET WELL & GENERATOR. SEE SHEET E2 FOR CONTINUATION. 14 H R BUBBLER CONTROL PANEL 3"C: BUBBLER CABLE 5 20 17 18 FIT 19 NOTES NOTES NAME NAME DATE DATE SURVEY BY SURVEY BY NA N/A DRAWN BY DRAWN BY ESZ 7/6/2021 DESIGNED BY DESIGNED BY ESZ 6/24/2021 CHECKED BY CHECKED BY JRSA 7/02/2021 REVIEWED BY REVIEWED BY ESZ 7/02/2021 JR SA EN G IN EER IN G , IN C. E13 CityView 2, Suite 100 Austin, Texas 78746 P - 512.338.1704 F - 512.338.1784 TBPE Firm #6535 www.kfriese.com SHEET 49 OF 63 Northwest Area Lift Station Improvements Great Hills LiftStation No. 53 (SP-2022-0537C)_________________________________________________46 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 660 OF 63Northwest Area Lift Station Improvements Great Hills LiftStation No. 53 (SP-2022-0537C)_________________________________________________47 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 648 of 4805 SP-2022-0537C - NW Area Lift Station Improvements Great Hills Lift Station No.53; District 6