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HomeMy WebLinkAboutSW5240603_Design Calculations_20240911 (2) North Section SNAP Tool Project Info Project Information Complete this sheet if required by your reviewing authority. Contact them for any questions. Grey boxes/text are optional. SNAPv4.2.0 LOCATION Project Name(optional): Eaddy Building Addition Parcel ID(optional): Submission Date(optional): date Nutrient Management Watershed: menu Local Jurisdiction/Reviewing Agency: State/Federal menu Subwatershed: Neuse-Upper menu Project Latitude Coordinates(optional): 35.814000 N Phosphorus Delivery Zone: Neuse- Upper 03020201 menu Project Longitude Coordinates(optional): -78.711000 W Nitrogen Delivery Zone: Neuse- Upper 03020201 menu PROJECT DETAILS Development Land Use Type: Institutional menu Disturbed Area: 33,976 ft2 Part of Common Development Plan? .no yin Project Activity: New Development menu Designated Downtown Area? no yin Project Drains to SA Waters? no yin Public Linear Road/Sidewalk Project? .no yin Pre-Project Land Use: developed menu Project Owner Type: State non-NCDOT menu Project Description(optional): STORMWATER DETAILS (Falls ONLY)Onsite Reduction%Req. % Project Uses LID/Runoff Volume Match? no yin Existing BUA/Development Onsite? yes yin Local Gov't nutrient req's same as State? yes yin Local Gov't cutoff date for Existing BUA: 05/01/2023 date Project Drains to Regional SCM? no yin Nitrogen Export Rate Target: 3.60 lb/ac/yr Total Nitrogen Offset Credits Needed: lb/yr Phosphorus Export Rate Target: 1000.00 lb/ac/yr Total Phosphorus Offset Credits Needed: lb/yr Land Cover Characteristics SNAP v4.2.0 Project Area and Offsite Land Cover Characteristics Precipitation Raleigh Station: Copy ' Paste VALUES ONLY for Best Results Click here to scroll down to error messages on this sheet. PROJECT AREA LAND COVERS ITN EMC (mg/L) TP EMC (mg/L) Pre-Project Area (ft2) Post-Project Area (ft2) Change pre-to-post(ft2) Roof 1.18 0.11 — 4,993 4,993 Roadway 1.64 0.34 0 Parking/Driveway/Sidewalk 1.42 0.18 902 902 Protected Forest 0.97 0.03 0 Managed Pervious/Landscaping 2.48 1.07 18,366,208 18,360,313 -5,895 Offsite or Existing Roof 1.18 0.11 482,172 482,172 0 Offsite or Existing Roadway 1.64 0.34 0 Offsite or Existing Parking/Driveway/Sidevin 1.42 0.18 572,554 572,554 0 Offsite Protected Forest 0.97 0.03 0 Offsite Managed Pervious 2.48 1.07 0 CUSTOM LAND COVER 1 0 CUSTOM LAND COVER 2 _ 0 CUSTOM LAND COVER 3 0 LAND TAKEN UP BY SCM 1.18 0.11 0 Total (Regulated & UnReg)Area 19,420,934.00 19,420,934.00 Project (Regulated)Area 18,366,208.00 18,366,208.00 Nutrient Export Summary Nutrient Export Summary SNAP v4.2.0 Landcover&SCM Data Review Errors/Advisories Errors/Advisories Avg Annual precip(in)= 46.22 SCM Area(ft2) = 0 Total(Regulated+ Unregulated)Area(ftZ)= 19,420,934 SCM Treated Area(ft2)= 0 Project(Regulated) 18,366,208 Catchment Routing: No errors Area(ft2)= Net BUA(Project Area Treating Runoff from 5,895 Net BUA indicates new development or expansion. no BUA only ft2)= Existing BUA or Offsite: Custom Landcovers are present: no Disturbed Area(ft2)= 33,976 Total Nitrogen Export Target lst�.s7 Total Phosphorus Export Target 421630.12 I Scaled to Project Area(Ib/yr): Scaled to Project Area(Ib/yr): Total Area Total Area Project Area Total Area Project Area Total Area Project Area Project Area Total Area Project Area (Onsite+ Post-Project Post-Project Post-Project Post-Project Post-Project Post-Project Nutrient Export Summary Offsite) (Onsite Only) before before Post-Project Post-Project SCM-Treated SCM-Treated Untreated Untreated Pre-Project after Treatment after Treatment Pre-Project Treatment Treatment Area Only Area Only Areas Areas Area(All Landcover Types)(acres) 445.8433 421.6301 445.8433 421.6301 445.8433 421.6301 0.0000 0.0000 445.8433 421.6301 Percent Built-Upon Area(BUA)(%) 5% 0% 5% 0% 5% I 0% 0% 0% 5% 0% Built-Upon Area(BUA)(sqft) 1,054,726 I 0 1,060,621 5,575 1,060,621 5,575 0 0 1,060,621 5,895 Annual Runoff Volume(ft3/yr) 6,656,720 3,183,323 6,675,112 3,201,715 6,675,112 3,201,715 0 0 6,675,112 3,201,715 Annual Runoff%Change A 0% 1% 0% 1% Total Runoff Change(cuft/yr) AR „ 18,392 18,392 18,392 18,392 Total Nitrogen EMC(mg/L) 1.87 1.25 1.87 2.47 1.87 2.47 0.00 0.00 1.87 2.47 Total Nitrogen Load Leaving Site(Ib/yr) 777.15 492.96 778.46 494.28 778.46 494.28 0.00 0.00 778.46 494.28 1 Total Nitrogen Loading Rate(Ib/ac/yr) 1.74 I 1.17 1.75 1.17 1.75 1.17 0.00 0.00 1.75 1.17 Total Nitrogen%Change Pre-to-Post 0% 0% 0% 0% Total Nitrogen Change(Ib/yr)Pre-to-Post 1.32 1.32 1.32 1.32 Total Phosphorus EMC(mg/L) 0.59 0.54 0.59 1.06 0.59 1.06 0.00 0.00 0.59 1.06 Total Phosphorus Load Leaving Site(Ib/yr) 244.79 212.69 244.87 212.77 244.87 212.77 0.00 0.00 244.87 212.77 Total Phosphorus Loading Rate(Ib/ac/yr) 0.55 0.50 0.55 0.50 0.55 0.50 0.00 0.00 0.55 0.50 Total Phosphorus%Change Pre-to-Post 0% 0% 0% 0% Total Phosphorus Change(Ib/yr)Pre-to-Post 0.08 0.08 0.08 0.08 SCM/Catchment Summary SCM ID and Type Volume TN Reduction TP Reduction TN Out TP Out Falls Lake ONLY: Onsite Reduction Compliance Check Reduction(%) (%) (%) (Ibs/ac/yr) (Ibs/ac/yr) Catchment 1 0.00% 0.00% 0.00% 0.00 0.00 I) Nitrogen II Phosphorus 101:NA 0.00% 0.00% 0.00% 0.00 0.00 Onsite%Reduction Requirement 102:NA 0.00% 0.00% 0.00% 0.00 0.00 Export Target Scaled to Area(Ib/yr) 1,517.87 421,630.12 103:NA 0.00% 0.00% 0.00% 0.00 0.00 Export Load Post-Project Before Treatment 494.28 212.77 Catchment 2 0.00% 0.00% 0.00% 0.00 0.00 Total Reduction Need(Ib/yr) 201:NA 0.00% 0.00% 0.00% 0.00 0.00 Onsite Reduction Need(Ib/yr) 202:NA 0.00% 0.00% 0.00% 0.00 0.00 Onsite Export Target(Ib/yr) 203:NA 0.00% 0.00% 0.00% 0.00 0.00 Project Area Post-Project After Treatment i 494.28 212.77 Catchment 3 0.00% 0.00% 0.00% 0.00 0.00 301:NA 0.00% 0.00% 0.00% 0.00 0.00 302:NA 0.00% 0.00% 0.00% 0.00 0.00 303:NA 0.00% 0.00% 0.00% 0.00 0.00 Catchment 4 0.00% 0.00% 0.00% 0.00 0.00 401:NA 0.00% 0.00% 0.00% 0.00 0.00 402:NA 0.00% 0.00% 0.00% 0.00 0.00 403:NA 0.00% 0.00% 0.00% 0.00 0.00 Catchment 5 0.00% 0.00% 0.00% 0.00 0.00 501:NA 0.00% 0.00% 0.00% 0.00 0.00 502:NA 0.00% 0.00% 0.00% 0.00 0.00 503:NA 0.00% 0.00% 0.00% 0.00 0.00 Catchment 6 0.00% 0.00% 0.00% 0.00 0.00 601:NA 0.00% 0.00% 0.00% 0.00 0.00 602:NA 0.00% 0.00% 0.00% 0.00 0.00 603:NA 0.00% 0.00% 0.00% 0.00 0.00 Nutrient Offset Nutrient Management Strategy Watershed - Nutrient Offset Credit Reporting Form SNAP v4.2.0 Please complete and submit the following information to the local government permitting your development project to characterize it and assess the need to purchase nutrient offset credits. Contact and rule implementation information can be found online at: http://deq.nc.gov/about/divisions/water-resources/planning/nonpoint-source-management/nutrient-offset-information PROJECT INFORMATION Applicant Name: Project Name: Eaddy Building Addition Project Address: Date: (mm/dd/yyyy) Development Land Use Type: Institutional County: Project Activity Type: New Development Project Area(sqft): 18,366,208 Project Latitude: 35.814000 Post-Project Built-Upon Area%: 0.03% I Project Longitude: -78.711000 WATERSHED INFORMATION Nutrient Management Watershed: 0 N Target Export Rate(Ib/ac/yr): 3.60 Subwatershed: Neuse-Upper P Target Export Rate(Ib/ac/yr): 1000.00 Nitrogen Delivery Zone: Neuse-Upper 03020201 Nitrogen Delivery Factor: 100% Phosphorus Delivery Zone: Neuse-Upper 03020201 Phosphorus Delivery Factor: 100% PERMANENT NUTRIENT OFFSET REQUEST Post-Project Nitrogen Calculations -Projects with No Offsite or Built-Upon Area (A) (B) (C) (D) (F) (G) (Where Applicable) TN Export TN Remaining TN Permanent Additional Total TN TN Untreated TN Treated TN Delivery Offsets Permanent Load(Ib/yr) Target Load Load(Ib/yr) Reduction Factor(%) Required Local Gov't Offsets to (Ib/yr) Need(Ib/yr) (Ib/yr) Offsets(Ib/yr) Buy(Ib/yr) 494.3 1517.9 494.3 0.0 1 100.0% 0.0 0.0 Post-Project Phosphorus Calculations -Projects with No Offsite or Built-Upon Area (A) (B) (C) (D) (F) (G) (Where Applicable) TP Export TP Remaining TP Permanent Additional Total TP TP Untreated TP Treated TP Delivery Offsets Permanent Load(Ib/yr) Target Load Load(Ib/yr) Reduction Factor(%) Required Local Gov't Offsets to (Ib/yr) Need(Ib/yr) (Ib/yr) Offsets(Ib/yr) Buy(Ib/yr) 212.8 421630.1 212.8 0.0 100.0% 0.0 0.0 LOCAL GOVERNMENT AUTHORIZATION Local Government Name:I Staff Name: Phone: Staff Email: Date: Local Government Authorizing Signature: