The URL can be used to link to this page

Home My WebLink AboutCV 36 Preliminary Drainge Report 7 16 2024 WHITE - DATERS & ASSOCIATES, INC. 24 Rahling Circle Little Rock, Arkansas 72223 Phone: 501-821- 1667 www.whitedaters.com CIVIL ENGINEERING - LAND PLANNING & DEVELOPMENT – SURVEYING – LANDSCAPE ARCHITECTURE Drainage Report July 16, 2024 Preliminary Plat Chenal Valley – Phase 36 Project Description Chenal Valley Phase 36 is a single-family residential development. It will be constructed by PotlatchDeltic for the sale of residential lots to Builders and possibly individuals. The total area of the subdivision, including adjacent tracts is 51.1 acres. The project is wooded and bordered on the north by Chenal Parkway. The project drains to the north and under Chenal Parkway through 3 existing culverts. The three culverts discharge into tracts in and adjacent to the Aberdeen Neighborhood. There are no known existing drainage issues/problems downstream of this project. Lower portions of the project slope between 8% and 10%. The southern portion of the project is steeper with slopes varying from to 16% to 20%. The project will be graded with the construction of the initial phase to allow the construction of homes on concrete slab foundations. In addition to the internal streets, Chenal Parkway will be widened at the intersection of Chenal Parkway and Chenonceau to provide turning lanes. The south let of the intersection will be signalized and any necessary modifications to the existing traffic signal constructed. Owner PotlatchDeltic Real Estate LLC 7 Chenal Club Boulevard Little Rock, Arkansas 72223 501-821-5555 Developer PotlatchDeltic Real Estate LLC 7 Chenal Club Boulevard Little Rock, Arkansas 72223 501-821-5555 Engineer Timothy E. Daters. P.E. White-Daters & Associates 24 Rahling Circle, Little Rock, AR 72223 501-821-1667 Address South side of Chenal Parkway, West of Chenonceau (Address not yet assigned) CIVIL ENGINEERING - LAND PLANNING & DEVELOPMENT – SURVEYING – LANDSCAPE ARCHITECTURE Page 2 Existing Conditions The site is in a wooded area, south of Chenal Parkway, west of Chenonceau and east of the recently constructed New Life Church. The site is in the northern portion of a large, wooded tract which extends to the south to Shinall Mountain and Bear Den Mountain. The site is within the corporate limits of the City of Little Rock. Three culverts crossing under Chenal Parkway drain this project. The Eastern Basin has a total drainage area of 18.5 acres. The area in the Eastern Basin in Phase 36 is 7.5 acres. The Middle Basin had an area of 96 acres. The area of the Middle Basin in Phase 36 is approximately 32 acres. The Western Basin has an area of 95 acres. The area of the Western Basin in Phase 36 is approximately 11 acres. Chenal Parkway Culverts Easten Basin 1-48” RCP Middle Basin 72” tall, 96” wide RC Box Culvert Westen Basin 72” tall, 96” wide RC Box Culvert 100-year event velocities in these culverts are less than 7 to 8 feet per second when flowing full and are by inspection adequate. Modeling of these culverts will be done in detail with the complete drainage analysis for the proposed improvements. Existing Area Drainage Problems Based on a visual inspection of the improvements in the vicinity of the project, this project when developed will not impact or exacerbate any existing drainage problems. Proposed Improvements The proposed improvements include grading the streets and lots, installation of storm drainage pipes and inlets, installation of sanitary sewer, water, gas and underground electrical facilities. Storm water detention facilities will be constructed and a main kiosk. The entry street includes a short boulevard section with center landscaped island. Future residential development will occur to the south and east of the entry street. Design Methodology Time of Concentration was calculated using nomographs in the Little Rock Drainage Manual. Runoff Coefficients are based on current and future land use and are consistent with those in the Little Rock Drainage Manual. CIVIL ENGINEERING - LAND PLANNING & DEVELOPMENT – SURVEYING – LANDSCAPE ARCHITECTURE Page 3 Storm water runoff rates, volumes and detention will be computed using Hydroflow Hydrographs with the Rational Method. Storm drains and inlets were designed using Hydroflow Storm Sewers. Predevelopment/Post Development Summary Development of this project will have minimal impact on the discharge from the culverts under Chenal Parkway since the bulk of the upgradient drainage area will remain undeveloped and forested. Stormwater detention will be provided to comply with the City of Little Rock ordinances. The longest flow path in the Eastern Basin is approximately 1,300 linear feet. Only the lower 140 linear feet of this path will be modified from paved ditch to pipe culvert. There will be no measurable change in the time of concentration for this basin. Less than 3 acres of this 18.5-acre basin will be converted from forest to residential lots and street. The increase in peak run-off rate will be minimal and easily mitigated through the construction of storm water detention facilities. The longest flow path in the Middle Basin is approximately 3,400 linear feet. Only 100 linear feet of this path will be modified with the construction of a pipe culvert. There will be no measurable change in the time of concentration for this basin. Less than 22 acres of this 96-acre basin will be converted from forest to residential lots and street. The increase in peak run-off rate will be minimal and easily mitigated through the construction of two storm water detention facilities located upstream and downstream from the proposed extension of Chenonceau. The longest flow path in the Western Basin is approximately 4,400 linear feet. The project will not alter any of the flow path. There will be no change in the time of concentration for this basin. Less than 9 acres of this 95-acre basin will be converted from forest to residential lots and street. The increase in peak run-off rate will be minimal and easily mitigated through the construction of a storm water detention facility located upstream from the box culvert under Chenal Parkway. Storage Estimate from Hydroflow Hydrographs For Middle Drainage Basin 7,000 Cubic Feet for 25 year event 14,000 Cubic Feet for 100 year event With an average depth of 1.5 feet only 10,000 SF of area would be required to provide detention for the 100 year event. Areas available as shown on the Preliminary Plat are easily double the required area. This is the only basin with a significant detention requirement. CIVIL ENGINEERING - LAND PLANNING & DEVELOPMENT – SURVEYING – LANDSCAPE ARCHITECTURE Page 4 Water Quality Design Methodology Whenever practicable impervious surfaces are separated from the storm drain culvert system by turf or landscaped areas. The parking lot which drains to the west will be kept free from debris and sediment. Riprap will be placed at the pipe discharge to prevent erosion. A three phase Erosion Control Plan will be implemented to minimize erosion during construction. Final Design Methodology Final construction plans for drainage improvements and stormwater detention will be prepared and submitted with a Grading Permit Application in accordance with the Little Rock Stormwater Drainage Manual. No improvements will be constructed prior to approval by the City of Little Rock. Attachments The following are included in this report. Exhibit 1 Preliminary Plat – Chenal Valley Phase 36 Exhibit 2 Sketch Map of Drainage Basins Exhibit 3 StreamStats Report Middle Basin Exhibit 4 StreamStats Report Western Drainage Basin Exhibit 5 Preliminary Hydrologic Analysis Exhibit 2 15.5 Acres 0.6 Miles91.7 Acres 1.5 Miles 96.9 Acres 1.9 Miles 0.2 Miles0.2 Miles0.0 Mi les 0.1 Miles0.0 Mi les0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.0 Miles0.0 Miles0. 1 M i l e s 0 . 1 M i l e s 0 . 1 M i l e s 0 . 1 M i l e s0.1 Mi les0.0 Miles0.0 Miles0.0 Miles0.1 M i l e s 0.0 Miles0.1 Miles0.1 Miles0.0 Miles0.0 Miles0.0 Miles0.0 Miles 0.1 Miles0.1 Miles 0.0 Miles0.0 Miles0.0 Miles0.0 Miles0.0 Miles0.0 Miles0.0 Miles0.0 Miles0.1 Miles0.1 Miles0.0 Miles0.0 Miles0.1 Miles0.1 Miles0.0 M i les0 .0 M i les 0.0 Mile s 0 . 0 M i l e s 0. 1 M i l e s 0 . 1 M i l e s 0.1 M i l e s 0 . 1 M i l e s 0. 0 M i l e s 0 . 0 M i l e s0.2 Miles0.2 Miles0.1 Miles0.1 Miles0.0 Miles0.0 Miles0.2 Miles0.2 Miles0.1 M i l e s 0 . 1 M i l e s 0.1 M i l e s 0.2 M i l e s 0 . 2 M i l e s 0.1 Miles0.0 M i l e s 0.1 Miles0.0 Miles0.0 Miles0.0 Miles0.0 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.2 M i l e s 0 . 2 M i l e s 0.1 M i l e s 0 . 1 M i l e s0.1 Mile s 0. 1 Mil e s 0.1 Miles0.1 Miles 0.0 Miles0.0 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.0 Miles0.0 Miles0.1 Miles0.1 Miles0.1 Miles0.1 Miles 0.1 Miles0.1 Miles0.1 Miles0.1 Miles0.1 M i l e s ArcGIS Web Map Sherwood_Sewer_Lines Force Main Gravity Sewer Line Pipeline Renewal Sewer Manhole Treatment Plant Pump Station Index Contours - 10 ft. Parcels Airport Military Reservation Park Golf Course or Sports Site Golf Course Golf Tee Box Golf Fairway Golf Green Golf Sand Trap Racetrack Raceway Tennis or Basketball Court Athletic Field Swamp or Marsh Lakes and Ponds Stream Edge Lake Maumelle Arkansas River Stream Centerline Lock Gate Dam or Weir Road or Parking Area Road or Parking Edge Trail Rail Road Bridge Building Shadow Invalid Rule Rule_1 Buildings Invalid Rule Rule_1 Raw Water Line Water Main Distribution Distribution, Pvt Fire Service Lead Fire Service Lead, Pvt Stub Stub, Pvt Hydrant Lead Water Valve - Public Altitude Blow Off Butterfly Check Gate Level Control Post Indicator Pressure Regulator RPZ Pito Fire Service Pressure Boundary Stub Unknown Water Valve - Private Hydrant Public Unknown Private CAW Construction Project Sewer Line Sewer Manhole July 21, 2024 0 0.15 0.30.07 mi 0 0.25 0.50.13 km 1:7,200 Web AppBuilder for ArcGIS Exhibit 2 Exhibit 2 StreamStats Report CV Phase 36 Middle Basin Collapse All Basin Characteristics Parameter Code Parameter Description Value Unit ALVM Percentage of the basin covered by Quaternary alluvial deposits from Reed & Bush (2005) 0 percent BFI Proportion of mean annual flow that is from ground water (base flow) 0.25 dimensionless BSHAPELFP Basin Shape Factor computed as the square of the longest flow path divided by drainage area 2.809 dimensionless Region ID:AR Workspace ID:AR20240721180221626000 Clicked Point (Latitude, Longitude):34.80332, -92.47967 Time:2024-07-21 13:03:17 -0500   7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/1/12 Exhibit 3 Parameter Code Parameter Description Value Unit CSL1085ADJ Adjusted 10-85 slope in feet per mile 518.103 feet per mi CSL1085LFP Change in elevation divided by length between points 10 and 85 percent of distance along the longest flow path to the basin divide, LFP from 2D grid 554 feet per mi CSL1085RAW Unadjusted 10-85 stream slope method in feet per mile. 554 feet per mi CSLBlue Change in elevation of the longest blue-line stream (not extended to the boundary) divided by stream length 621 feet per mi DRNAREA Area that drains to a point on a stream 0.15 square miles ELEV Mean Basin Elevation 512 feet HIGHREG HIGHREG 1715 dimensionless LC11DEV Percentage of developed (urban) land from NLCD 2011 classes 21-24 16.8 percent LC11DVOPN Percentage of developed open area from NLCD 2011 class 21 10.5 percent LC11IMP Average percentage of impervious area determined from NLCD 2011 impervious dataset 2.29 percent LC11PAST Percentage of area of pasture area from NLCD 2011 class 81 0 percent LFPLENGTH Length of longest flow path 0.644 miles LOWREG Low Flow Region Number 1439 dimensionless MARAVPRE Mean March Precipitation inches NOVAVPRE Mean November Precipitation inches ORDOMISS Percent Surficial Geology as Ordovician and Mississippian Rocks 0 percent PRECIP Mean Annual Precipitation 50.2 inches PREMARAPR Precipitation March-April basin average, mean monthly as defined in SIR 2008-5065 inches PRENOVDEC Precipitation November-December basin average, mean monthly as defined in SIR 2008-5065 inches 7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/2/12 Parameter Code Parameter Description Value Unit PRNOVAPR00 Precipitation November-April basin average, mean seasonal from PRISM 1971-2000 inches PRNOVAPR90 Precipitation November-April basin average, mean seasonal from PRISM 1961-1990 inches PZNSSREGNO Zeroflow Region Number 1446 dimensionless SOILINDEX Mean STATSGO Hydrologic Soils Index (from PL. 2 WRIR 03-4107 for WY) 2 dimensionless TAU_ANN_G Tau, Average annual base-flow recession time constant as defined in SIR 2008-5065 10 days TAU_SPR_G Tau, Average base-flow recession time constant for March through April as defined in SIR 2008-5065, estimated from a grid 8 days TAU_WIN_G Tau, Average base-flow recession time constant for November through December as defined in SIR 2008-5065, estimated from a grid 10 days TRUN0711 Mean annual dry season total runoff, July through November 4.11 inches UPZ Percentage of the basin covered by upper Paleozoic strata from Reed & Bush (2005) 100 percent General Disclaimers This watershed has been edited, computed flows and basin characteristics may not apply. For more information, submit a support request from the 'Help' button in the upper-right of the screen, attach a pdf of this report and request assistance from your local StreamStats regional representative. Peak-Flow Statistics Peak-Flow Statistics Parameters [Peak Region A 2016 5081] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 0.04 1250  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/3/12 Parameter Code Parameter Name Value Units Min Limit Max Limit ELEV Mean Basin Elevation 512 feet 380 1840 Peak-Flow Statistics Flow Report [Peak Region A 2016 5081] PIL: Lower 90% Prediction Interval, PIU: Upper 90% Prediction Interval, ASEp: Average Standard Error of Prediction, SE: Standard Error, PC: Percent Correct (other -- see report) Statistic Value Unit PIL PIU ASEp 50-percent AEP flood 52.3 ft^3/s 25.7 107 42 20-percent AEP flood 94.1 ft^3/s 53.5 166 32 10-percent AEP flood 127 ft^3/s 73 221 31 4-percent AEP flood 177 ft^3/s 101 310 32 2-percent AEP flood 218 ft^3/s 120 395 34 1-percent AEP flood 261 ft^3/s 141 482 37 0.2-percent AEP flood 375 ft^3/s 180 782 45 Peak-Flow Statistics Citations Wagner, D.M., Krieger, J.D., and Veilleux, A.G.,2016, Methods for estimating annual exceedance probability discharges for streams in Arkansas, based on data through water year 2013: U.S. Geological Survey Scientific Investigations Report 2016–5081, 136 p. (http://dx.doi.org/10.3133/sir20165081) Low-Flow Statistics Low-Flow Statistics Parameters [Low Flow Region 2 2008 5065] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 4.7 932 TAU_ANN_G Tau Annual from Grid 10 days 5.5 26.7 PRECIP Mean Annual Precipitation 50.2 inches 44.5 61.9 LOWREG Low Flow Region Number 1439 dimensionless  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/4/12 Low-Flow Statistics Disclaimers [Low Flow Region 2 2008 5065] One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors. Low-Flow Statistics Flow Report [Low Flow Region 2 2008 5065] Statistic Value Unit 7 Day 2 Year Low Flow 0.000248 ft^3/s 7 Day 10 Year Low Flow 0.000359 ft^3/s Low-Flow Statistics Citations Funkhouser, J.E., Eng, Ken, and Moix, M.W.,2008, Low-Flow Characteristics and Regionalization of Low Flow Characteristics for Selected Streams in Arkansas: U. S. Geological Survey Scientific Investigations Report 2008-5065, 161 p. (http://pubs.usgs.gov/sir/2008/5065/pdf/SIR2008-5065.pdf) Monthly Flow Statistics Monthly Flow Statistics Parameters [Dry Season Mean Monthly Flow 2015 5031] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 4.1 7350 TRUN0711 Dry Season Total Runoff 4.11 inches 3.6 5.6 Monthly Flow Statistics Parameters [Low Flow Region 1 2008 5065] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 12.1 828.5 ORDOMISS Percent SurficialGeology Ordo and Miss 0 percent 0 100 PRNOVAPR00 Basin Ave Rainfall Nov Apr PRISM 2000 inches 21.3 26.2 MARAVPRE Mean March Precipitation inches 4.1 5.3 LOWREG Low Flow Region Number 1439 dimensionless  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/5/12 Monthly Flow Statistics Parameters [Low Flow Region 2 2008 5065] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 4.7 932 NOVAVPRE Mean November Precipitation inches 4.3 5.6 TAU_WIN_G Tau Nov Dec from Grid 10 days 6.5 12.3 ORDOMISS Percent SurficialGeology Ordo and Miss 0 percent 0 100 TAU_ANN_G Tau Annual from Grid 10 days 5.5 26.7 PRNOVAPR90 Basin Ave Rainfall Nov Apr PRISM 1990 inches 8.3 31.1 MARAVPRE Mean March Precipitation inches 4.1 6.6 LOWREG Low Flow Region Number 1439 dimensionless Monthly Flow Statistics Parameters [Low Flow Region 3 2008 5065] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 4.7 932 PRNOVAPR90 Basin Ave Rainfall Nov Apr PRISM 1990 inches 25.8 32.8 TAU_ANN_G Tau Annual from Grid 10 days 6.2 12.1 ORDOMISS Percent SurficialGeology Ordo and Miss 0 percent 0 100 LOWREG Low Flow Region Number 1439 dimensionless Monthly Flow Statistics Flow Report [Dry Season Mean Monthly Flow 2015 5031] Statistic Value Unit Monthly Flow Statistics Flow Report [Low Flow Region 1 2008 5065] Statistic Value Unit 7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/6/12 Monthly Flow Statistics Flow Report [Low Flow Region 2 2008 5065] S t a t i s t i c V a l u e U n i t Monthly Flow Statistics Flow Report [Low Flow Region 3 2008 5065] S t a t i s t i c V a l u e U n i t Monthly Flow Statistics Citations Seasonal Flow Statistics Seasonal Flow Statistics Parameters [Low Flow Region 1 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 5 s q u a r e m i l e s 1 2 .1 8 2 8 .5 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 P R N O VA P R 0 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 2 0 0 0 i n c h e s 2 1 .3 2 6 .2 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Seasonal Flow Statistics Parameters [Low Flow Region 2 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 5 s q u a r e m i l e s 4 .7 9 3 2 P R E N O V D E C B a s i n A v e R a i n f a l l N o v D e c i n c h e s 7 .6 1 0 .9 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 P R N O VA P R 9 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 1 9 9 0 i n c h e s 8 .3 3 1 .1 TA U _S P R _G Ta u M a r A p r f r o m G r i d 8 d a y s 4 .5 2 5 .2 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/7/12 Seasonal Flow Statistics Parameters [Low Flow Region 3 2008 5065] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 4.7 932 PRNOVAPR90 Basin Ave Rainfall Nov Apr PRISM 1990 inches 25.8 32.8 TAU_ANN_G Tau Annual from Grid 10 days 6.2 12.1 PREMARAPR Basin Ave Rainfall Mar Apr inches 10 12.3 LOWREG Low Flow Region Number 1439 dimensionless Seasonal Flow Statistics Flow Report [Low Flow Region 1 2008 5065] Statistic Value Unit Seasonal Flow Statistics Flow Report [Low Flow Region 2 2008 5065] Statistic Value Unit Seasonal Flow Statistics Flow Report [Low Flow Region 3 2008 5065] Statistic Value Unit Seasonal Flow Statistics Citations General Flow Statistics General Flow Statistics Parameters [Harmonic Mean Flow Region 2 2015 5031] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 4.1 2090 BFI Base Flow Index 0.25 dimensionless 0.1 0.4 ORDOMISS Percent SurficialGeology Ordo and Miss 0 percent 0 100  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/8/12 General Flow Statistics Disclaimers [Harmonic Mean Flow Region 2 2015 5031] O n e o r m o r e o f t h e p a ra m e t e r s i s o u t s i d e t h e s u g g e s t e d r a n g e . E s t i m a t e s w e r e e x t r a p o l a t e d w i t h u n k n o w n e r r o r s . General Flow Statistics Flow Report [Harmonic Mean Flow Region 2 2015 5031] S t a t i s t i c V a l u e U n i t H a r m o n i c M e a n S t r e a m f l o w 0 .0 0 1 7 5 f t ^3 /s General Flow Statistics Citations B r e a k e r, B .K .,2 0 1 5 , D r y s e a s o n m e a n m o n t h l y f l o w a n d h a r m o n i c m e a n f l o w r e g r e s s i o n e q u a t i o n s f o r s e l e c t e d u n g a g e d b a s i n s i n A r k a n s a s : U .S . G e o l o g i c a l S u r v e y S c i e n t i f i c I n v e s t i g a t i o n s R e p o r t 2 0 1 5 –5 0 3 1 , 2 5 p . (h t t p ://p u b s .u s g s .g o v /s i r /2 0 1 5 /5 0 3 1 /) Bankfull Statistics Bankfull Statistics Parameters [Interior Highlands D Bieger 2015] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 5 s q u a r e m i l e s 3 0 .1 1 5 8 9 5 9 .0 7 2 4 Bankfull Statistics Parameters [USA Bieger 2015] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 5 s q u a r e m i l e s 0 .0 7 7 2 2 5 9 9 2 7 .7 3 9 3 Bankfull Statistics Disclaimers [Interior Highlands D Bieger 2015] O n e o r m o r e o f t h e p a ra m e t e r s i s o u t s i d e t h e s u g g e s t e d r a n g e . E s t i m a t e s w e r e e x t r a p o l a t e d w i t h u n k n o w n e r r o r s . Bankfull Statistics Flow Report [Interior Highlands D Bieger 2015] S t a t i s t i c V a l u e U n i t B i e g e r _D _c h a n n e l _w i d t h 6 8 f t B i e g e r _D _c h a n n e l _d e p t h 0 .6 8 8 f t B i e g e r _D _c h a n n e l _c r o s s _s e c t i o n a l _a r e a 4 6 .9 f t ^2  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/9/12 Bankfull Statistics Flow Report [USA Bieger 2015] Statistic Value Unit Bieger_USA_channel_width 6.35 ft Bieger_USA_channel_depth 0.805 ft Bieger_USA_channel_cross_sectional_area 6.13 ft^2 Bankfull Statistics Flow Report [Area-Averaged] Statistic Value Unit Bieger_D_channel_width 68 ft Bieger_D_channel_depth 0.688 ft Bieger_D_channel_cross_sectional_area 46.9 ft^2 Bieger_USA_channel_width 6.35 ft Bieger_USA_channel_depth 0.805 ft Bieger_USA_channel_cross_sectional_area 6.13 ft^2 Bankfull Statistics Citations Bieger, Katrin; Rathjens, Hendrik; Allen, Peter M.; and Arnold, Jeffrey G.,2015, Development and Evaluation of Bankfull Hydraulic Geometry Relationships for the Physiographic Regions of the United States, Publications from USDA-ARS / UNL Faculty, 17p. (https://digitalcommons.unl.edu/usdaarsfacpub/1515? utm_source=digitalcommons.unl.edu%2Fusdaarsfacpub%2F1515&utm_medium=PDF&utm_ Probability Statistics Probability Statistics Parameters [Pzero Flow Region 2 2008 5065] Parameter Code Parameter Name Value Units Min Limit Max Limit TAU_ANN_G Tau Annual from Grid 10 days 5.5 26.7 DRNAREA Drainage Area 0.15 square miles 4.7 932 PZNSSREGNO Prob zero flow region number 1446 dimensionless  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/10/12 Probability Statistics Disclaimers [Pzero Flow Region 2 2008 5065] One or more of the parameters is outside the suggested range. Estimates were extrapolated with unknown errors. Probability Statistics Flow Report [Pzero Flow Region 2 2008 5065] Statistic Value Unit Probability zero flow 7Day 0.119 dim Probability zero flow 7 day Nov to Apr 0.341 dim Probability zero flow 7 day Nov to Dec 0.572 dim Probability zero flow 7 day Nov 0.596 dim Probability Statistics Citations Funkhouser, J.E., Eng, Ken, and Moix, M.W.,2008, Low-Flow Characteristics and Regionalization of Low Flow Characteristics for Selected Streams in Arkansas: U. S. Geological Survey Scientific Investigations Report 2008-5065, 161 p. (http://pubs.usgs.gov/sir/2008/5065/pdf/SIR2008-5065.pdf) Maximum Probable Flood Statistics Maximum Probable Flood Statistics Parameters [Crippen Bue Region 8] Parameter Code Parameter Name Value Units Min Limit Max Limit DRNAREA Drainage Area 0.15 square miles 0.1 10000 Maximum Probable Flood Statistics Flow Report [Crippen Bue Region 8] Statistic Value Unit Maximum Flood Crippen Bue Regional 729 ft^3/s Maximum Probable Flood Statistics Citations Crippen, J.R. and Bue, Conrad D.1977, Maximum Floodflows in the Conterminous United States, Geological Survey Water-Supply Paper 1887, 52p. (https://pubs.usgs.gov/wsp/1887/report.pdf)  7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/11/12 USGS Data Disclaimer: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. USGS Software Disclaimer: This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use. USGS Product Names Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Application Version: 4.21.0 StreamStats Services Version: 1.2.22 NSS Services Version: 2.2.1 7/21/24, 1:06 PM StreamStats https://streamstats.usgs.gov/ss/12/12 StreamStats Report CV 36 Western Basin Collapse All Basin Characteristics Parameter Code Parameter Description Value Unit ALVM Percentage of the basin covered by Quaternary alluvial deposits from Reed & Bush (2005) 0 percent BFI Proportion of mean annual flow that is from ground water (base flow) 0.23 dimensionless BSHAPELFP Basin Shape Factor computed as the square of the longest flow path divided by drainage area 5.027 dimensionless CSL1085ADJ Adjusted 10-85 slope in feet per mile 824.648 feet per mi CSL1085LFP Change in elevation divided by length between points 10 and 85 percent of distance along the longest flow path to the basin divide, LFP from 2D grid 898 feet per mi Region ID:AR Workspace ID:AR20240721175333525000 Clicked Point (Latitude, Longitude):34.80478, -92.48392 Time:2024-07-21 12:53:58 -0500   7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/1/11 Exhibit 4 Parameter Code Parameter Description Value Unit CSL1085RAW Unadjusted 10-85 stream slope method in feet per mile. 898 feet per mi CSLBlue Change in elevation of the longest blue-line stream (not extended to the boundary) divided by stream length 787 feet per mi DRNAREA Area that drains to a point on a stream 0.14 square miles ELEV Mean Basin Elevation 660 feet HIGHREG HIGHREG 1715 dimensionless LC11DEV Percentage of developed (urban) land from NLCD 2011 classes 21-24 9.97 percent LC11DVOPN Percentage of developed open area from NLCD 2011 class 21 7.37 percent LC11IMP Average percentage of impervious area determined from NLCD 2011 impervious dataset 1.32 percent LC11PAST Percentage of area of pasture area from NLCD 2011 class 81 0 percent LFPLENGTH Length of longest flow path 0.837 miles LOWREG Low Flow Region Number 1439 dimensionless MARAVPRE Mean March Precipitation inches NOVAVPRE Mean November Precipitation inches ORDOMISS Percent Surficial Geology as Ordovician and Mississippian Rocks 0 percent PRECIP Mean Annual Precipitation 50.3 inches PREMARAPR Precipitation March-April basin average, mean monthly as defined in SIR 2008-5065 inches PRENOVDEC Precipitation November-December basin average, mean monthly as defined in SIR 2008-5065 inches PRNOVAPR00 Precipitation November-April basin average, mean seasonal from PRISM 1971-2000 inches PRNOVAPR90 Precipitation November-April basin average, mean seasonal from PRISM 1961-1990 inches PZNSSREGNO Zeroflow Region Number 1446 dimensionless SOILINDEX Mean STATSGO Hydrologic Soils Index (from PL. 2 WRIR 03-4107 for WY) 2 dimensionless TAU_ANN_G Tau, Average annual base-flow recession time constant as defined in SIR 2008-5065 10 days 7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/2/11 P a r a m e t e r C o d e P a r a m e t e r D e s c r i p t i o n V a l u e U n i t TA U _S P R _G Ta u , A v e r a g e b a s e -f l o w r e c e s s i o n t i m e c o n s t a n t f o r M a r c h t h r o u g h A p r i l a s d e f i n e d i n S I R 2 0 0 8 -5 0 6 5 , e s t i m a t e d f r o m a g r i d 8 d a y s TA U _W I N _G Ta u , A v e r a g e b a s e -f l o w r e c e s s i o n t i m e c o n s t a n t f o r N o v e m b e r t h r o u g h D e c e m b e r a s d e f i n e d i n S I R 2 0 0 8 - 5 0 6 5 , e s t i m a t e d f r o m a g r i d 1 0 d a y s T R U N 0 7 1 1 M e a n a n n u a l d r y s e a s o n t o t a l r u n o f f , J u l y t h r o u g h N o v e m b e r 4 .1 1 i n c h e s U P Z P e r c e n t a g e o f t h e b a s i n c o v e r e d b y u p p e r P a l e o z o i c s t r a t a f r o m R e e d & B u s h (2 0 0 5 ) 1 0 0 p e r c e n t Peak-Flow Statistics Peak-Flow Statistics Parameters [Peak Region A 2016 5081] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 0 .0 4 1 2 5 0 E L E V M e a n B a s i n E l e v a t i o n 6 6 0 f e e t 3 8 0 1 8 4 0 Peak-Flow Statistics Flow Report [Peak Region A 2016 5081] P I L : L o w e r 9 0 % P r e d i c t i o n I n t e r v a l , P I U : U p p e r 9 0 % P r e d i c t i o n I n t e r v a l , A S E p : A v e r a g e S t a n d a r d E r r o r o f P r e d i c t i o n , S E : S t a n d a r d E r r o r, P C : P e r c e n t C o r r e c t (o t h e r -- s e e r e p o r t ) S t a t i s t i c V a l u e U n i t P I L P I U A S E p 5 0 -p e r c e n t A E P f l o o d 4 9 .8 f t ^3 /s 2 4 .4 1 0 2 4 2 2 0 -p e r c e n t A E P f l o o d 9 6 f t ^3 /s 5 4 .6 1 6 9 3 2 1 0 -p e r c e n t A E P f l o o d 1 3 4 f t ^3 /s 7 7 2 3 3 3 1 4 -p e r c e n t A E P f l o o d 1 9 3 f t ^3 /s 1 1 0 3 3 8 3 2 2 -p e r c e n t A E P f l o o d 2 4 3 f t ^3 /s 1 3 4 4 4 0 3 4 1 -p e r c e n t A E P f l o o d 2 9 6 f t ^3 /s 1 6 0 5 4 7 3 7 0 .2 -p e r c e n t A E P f l o o d 4 4 1 f t ^3 /s 2 1 2 9 1 9 4 5 Peak-Flow Statistics Citations W a g n e r, D.M ., K r i e g e r, J .D., a n d V e i l l e u x , A .G .,2 0 1 6 , M e t h o d s f o r e s t i m a t i n g a n n u a l e x c e e d a n c e p r o b a b i l i t y d i s c h a r g e s f o r s t r e a m s i n A r k a n s a s , b a s e d o n d a t a t h r o u g h w a t e r y e a r  7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/3/11 2 0 1 3 : U .S . G e o l o g i c a l S u r v e y S c i e n t i f i c I n v e s t i g a t i o n s R e p o r t 2 0 1 6 –5 0 8 1 , 1 3 6 p . (h t t p ://d x .d o i .o r g /1 0 .3 1 3 3 /s i r 2 0 1 6 5 0 8 1 ) Low-Flow Statistics Low-Flow Statistics Parameters [Low Flow Region 2 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .7 9 3 2 TA U _A N N _G Ta u A n n u a l f r o m G r i d 1 0 d a y s 5 .5 2 6 .7 P R E C I P M e a n A n n u a l P r e c i p i t a t i o n 5 0 .3 i n c h e s 4 4 .5 6 1 .9 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Low-Flow Statistics Disclaimers [Low Flow Region 2 2008 5065] O n e o r m o r e o f t h e p a r a m e t e r s i s o u t s i d e t h e s u g g e s t e d r a n g e . E s t i m a t e s w e r e e x t r a p o l a t e d w i t h u n k n o w n e r r o r s . Low-Flow Statistics Flow Report [Low Flow Region 2 2008 5065] S t a t i s t i c V a l u e U n i t 7 D a y 2 Y e a r L o w F l o w 0 .0 0 0 2 2 9 f t ^3 /s 7 D a y 1 0 Ye a r L o w F l o w 0 .0 0 0 3 3 4 f t ^3 /s Low-Flow Statistics Citations F u n k h o u s e r, J .E ., E n g , K e n , a n d M o i x , M .W.,2 0 0 8 , L o w -F l o w C h a r a c t e r i s t i c s a n d R e g i o n a l i z a t i o n o f L o w F l o w C h a r a c t e r i s t i c s f o r S e l e c t e d S t r e a m s i n A r k a n s a s : U . S . G e o l o g i c a l S u r v e y S c i e n t i f i c I n v e s t i g a t i o n s R e p o r t 2 0 0 8 -5 0 6 5 , 1 6 1 p . (h t t p ://p u b s .u s g s .g o v /s i r /2 0 0 8 /5 0 6 5 /p d f /S I R 2 0 0 8 -5 0 6 5 .p d f ) Maximum Probable Flood Statistics Maximum Probable Flood Statistics Parameters [Crippen Bue Region 8] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 0 .1 1 0 0 0 0   7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/4/11 Maximum Probable Flood Statistics Flow Report [Crippen Bue Region 8] S t a t i s t i c V a l u e U n i t M a x i m u m F l o o d C r i p p e n B u e R e g i o n a l 6 8 5 f t ^3 /s Maximum Probable Flood Statistics Citations C r i p p e n , J .R . a n d B u e , C o n r a d D.1 9 7 7 , M a x i m u m F l o o d f l o w s i n t h e C o n t e r m i n o u s U n i t e d S t a t e s , G e o l o g i c a l S u r v e y W a t e r -S u p p l y P a p e r 1 8 8 7 , 5 2 p . (h t t p s ://p u b s .u s g s .g o v /w s p /1 8 8 7 /r e p o r t .p d f ) Probability Statistics Probability Statistics Parameters [Pzero Flow Region 2 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t TA U _A N N _G Ta u A n n u a l f r o m G r i d 1 0 d a y s 5 .5 2 6 .7 D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .7 9 3 2 P Z N S S R E G N O P r o b z e r o f l o w r e g i o n n u m b e r 1 4 4 6 d i m e n s i o n l e s s Probability Statistics Disclaimers [Pzero Flow Region 2 2008 5065] O n e o r m o r e o f t h e p a r a m e t e r s i s o u t s i d e t h e s u g g e s t e d r a n g e . E s t i m a t e s w e r e e x t r a p o l a t e d w i t h u n k n o w n e r r o r s . Probability Statistics Flow Report [Pzero Flow Region 2 2008 5065] S t a t i s t i c V a l u e U n i t P r o b a b i l i t y z e r o f l o w 7 D a y 0 .1 1 9 d i m P r o b a b i l i t y z e r o f l o w 7 d a y N o v t o A p r 0 .3 4 7 d i m P r o b a b i l i t y z e r o f l o w 7 d a y N o v t o D e c 0 .5 8 d i m P r o b a b i l i t y z e r o f l o w 7 d a y N o v 0 .6 0 5 d i m Probability Statistics Citations F u n k h o u s e r, J .E ., E n g , K e n , a n d M o i x , M .W.,2 0 0 8 , L o w -F l o w C h a r a c t e r i s t i c s a n d R e g i o n a l i z a t i o n o f L o w F l o w C h a r a c t e r i s t i c s f o r S e l e c t e d S t r e a m s i n A r k a n s a s : U . S . G e o l o g i c a l S u r v e y S c i e n t i f i c I n v e s t i g a t i o n s R e p o r t 2 0 0 8 -5 0 6 5 , 1 6 1 p . (h t t p ://p u b s .u s g s .g o v /s i r /2 0 0 8 /5 0 6 5 /p d f /S I R 2 0 0 8 -5 0 6 5 .p d f )  7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/5/11 Bankfull Statistics Bankfull Statistics Parameters [Interior Highlands D Bieger 2015] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 3 0 .1 1 5 8 9 5 9 .0 7 2 4 Bankfull Statistics Parameters [USA Bieger 2015] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 0 .0 7 7 2 2 5 9 9 2 7 .7 3 9 3 Bankfull Statistics Disclaimers [Interior Highlands D Bieger 2015] O n e o r m o r e o f t h e p a r a m e t e r s i s o u t s i d e t h e s u g g e s t e d r a n g e . E s t i m a t e s w e r e e x t r a p o l a t e d w i t h u n k n o w n e r r o r s . Bankfull Statistics Flow Report [Interior Highlands D Bieger 2015] S t a t i s t i c V a l u e U n i t B i e g e r _D _c h a n n e l _w i d t h 6 7 .4 f t B i e g e r _D _c h a n n e l _d e p t h 0 .6 7 6 f t B i e g e r _D _c h a n n e l _c r o s s _s e c t i o n a l _a r e a 4 5 .6 f t ^2 Bankfull Statistics Flow Report [USA Bieger 2015] S t a t i s t i c V a l u e U n i t B i e g e r _U S A _c h a n n e l _w i d t h 6 .2 f t B i e g e r _U S A _c h a n n e l _d e p t h 0 .7 9 3 f t B i e g e r _U S A _c h a n n e l _c r o s s _s e c t i o n a l _a r e a 5 .9 1 f t ^2 Bankfull Statistics Flow Report [Area-Averaged] S t a t i s t i c V a l u e U n i t B i e g e r _D _c h a n n e l _w i d t h 6 7 .4 f t B i e g e r _D _c h a n n e l _d e p t h 0 .6 7 6 f t B i e g e r _D _c h a n n e l _c r o s s _s e c t i o n a l _a r e a 4 5 .6 f t ^2 B i e g e r _U S A _c h a n n e l _w i d t h 6 .2 f t B i e g e r _U S A _c h a n n e l _d e p t h 0 .7 9 3 f t  7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/6/11 S t a t i s t i c V a l u e U n i t B i e g e r _U S A _c h a n n e l _c r o s s _s e c t i o n a l _a r e a 5 .9 1 f t ^2 Bankfull Statistics Citations B i e g e r, K a t r i n ; R a t h j e n s , H e n d r i k ; A l l e n , P e t e r M .; a n d A r n o l d , J e f f r e y G .,2 0 1 5 , D e v e l o p m e n t a n d E v a l u a t i o n o f B a n k f u l l H y d r a u l i c G e o m e t r y R e l a t i o n s h i p s f o r t h e P h y s i o g r a p h i c R e g i o n s o f t h e U n i t e d S t a t e s , P u b l i c a t i o n s f r o m U S D A -A R S / U N L F a c u l t y, 1 7 p . (h t t p s ://d i g i t a l c o m m o n s .u n l .e d u /u s d a a r s f a c p u b /1 5 1 5 ? u t m _s o u r c e =d i g i t a l c o m m o n s .u n l .e d u %2 F u s d a a r s f a c p u b %2 F 1 5 1 5 &u t m _m e d i u m =P D F &u t m _c a m p a i General Flow Statistics General Flow Statistics Parameters [Harmonic Mean Flow Region 2 2015 5031] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .1 2 0 9 0 B F I B a s e F l o w I n d e x 0 .2 3 d i m e n s i o n l e s s 0 .1 0 .4 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 General Flow Statistics Disclaimers [Harmonic Mean Flow Region 2 2015 5031] O n e o r m o r e o f t h e p a r a m e t e r s i s o u t s i d e t h e s u g g e s t e d r a n g e . E s t i m a t e s w e r e e x t r a p o l a t e d w i t h u n k n o w n e r r o r s . General Flow Statistics Flow Report [Harmonic Mean Flow Region 2 2015 5031] S t a t i s t i c V a l u e U n i t H a r m o n i c M e a n S t r e a m f l o w 0 .0 0 1 4 6 f t ^3 /s General Flow Statistics Citations B r e a k e r, B .K .,2 0 1 5 , D r y s e a s o n m e a n m o n t h l y f l o w a n d h a r m o n i c m e a n f l o w r e g r e s s i o n e q u a t i o n s f o r s e l e c t e d u n g a g e d b a s i n s i n A r k a n s a s : U .S . G e o l o g i c a l S u r v e y S c i e n t i f i c I n v e s t i g a t i o n s R e p o r t 2 0 1 5 –5 0 3 1 , 2 5 p . (h t t p ://p u b s .u s g s .g o v /s i r /2 0 1 5 /5 0 3 1 /)  7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/7/11 Seasonal Flow Statistics Seasonal Flow Statistics Parameters [Low Flow Region 1 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 1 2 .1 8 2 8 .5 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 P R N O V A P R 0 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 2 0 0 0 i n c h e s 2 1 .3 2 6 .2 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Seasonal Flow Statistics Parameters [Low Flow Region 2 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .7 9 3 2 P R E N O V D E C B a s i n A v e R a i n f a l l N o v D e c i n c h e s 7 .6 1 0 .9 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 P R N O V A P R 9 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 1 9 9 0 i n c h e s 8 .3 3 1 .1 TA U _S P R _G Ta u M a r A p r f r o m G r i d 8 d a y s 4 .5 2 5 .2 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Seasonal Flow Statistics Parameters [Low Flow Region 3 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .7 9 3 2 P R N O V A P R 9 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 1 9 9 0 i n c h e s 2 5 .8 3 2 .8 TA U _A N N _G Ta u A n n u a l f r o m G r i d 1 0 d a y s 6 .2 1 2 .1 P R E M A R A P R B a s i n A v e R a i n f a l l M a r A p r i n c h e s 1 0 1 2 .3 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Seasonal Flow Statistics Flow Report [Low Flow Region 1 2008 5065] S t a t i s t i c V a l u e U n i t  7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/8/11 Seasonal Flow Statistics Flow Report [Low Flow Region 2 2008 5065] S t a t i s t i c V a l u e U n i t Seasonal Flow Statistics Flow Report [Low Flow Region 3 2008 5065] S t a t i s t i c V a l u e U n i t Seasonal Flow Statistics Citations Monthly Flow Statistics Monthly Flow Statistics Parameters [Dry Season Mean Monthly Flow 2015 5031] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .1 7 3 5 0 T R U N 0 7 1 1 D r y S e a s o n To t a l R u n o f f 4 .1 1 i n c h e s 3 .6 5 .6 Monthly Flow Statistics Parameters [Low Flow Region 1 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 1 2 .1 8 2 8 .5 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 P R N O V A P R 0 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 2 0 0 0 i n c h e s 2 1 .3 2 6 .2 M A R AV P R E M e a n M a r c h P r e c i p i t a t i o n i n c h e s 4 .1 5 .3 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Monthly Flow Statistics Parameters [Low Flow Region 2 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .7 9 3 2 N O VAV P R E M e a n N o v e m b e r P r e c i p i t a t i o n i n c h e s 4 .3 5 .6 TA U _W I N _G Ta u N o v D e c f r o m G r i d 1 0 d a y s 6 .5 1 2 .3 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0  7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/9/11 P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t TA U _A N N _G Ta u A n n u a l f r o m G r i d 1 0 d a y s 5 .5 2 6 .7 P R N O V A P R 9 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 1 9 9 0 i n c h e s 8 .3 3 1 .1 M A R AV P R E M e a n M a r c h P r e c i p i t a t i o n i n c h e s 4 .1 6 .6 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Monthly Flow Statistics Parameters [Low Flow Region 3 2008 5065] P a r a m e t e r C o d e P a r a m e t e r N a m e V a l u e U n i t s M i n L i m i t M a x L i m i t D R N A R E A D r a i n a g e A r e a 0 .1 4 s q u a r e m i l e s 4 .7 9 3 2 P R N O V A P R 9 0 B a s i n A v e R a i n f a l l N o v A p r P R I S M 1 9 9 0 i n c h e s 2 5 .8 3 2 .8 TA U _A N N _G Ta u A n n u a l f r o m G r i d 1 0 d a y s 6 .2 1 2 .1 O R D O M I S S P e r c e n t S u r f i c i a l G e o l o g y O r d o a n d M i s s 0 p e r c e n t 0 1 0 0 L O W R E G L o w F l o w R e g i o n N u m b e r 1 4 3 9 d i m e n s i o n l e s s Monthly Flow Statistics Flow Report [Dry Season Mean Monthly Flow 2015 5031] S t a t i s t i c V a l u e U n i t Monthly Flow Statistics Flow Report [Low Flow Region 1 2008 5065] S t a t i s t i c V a l u e U n i t Monthly Flow Statistics Flow Report [Low Flow Region 2 2008 5065] S t a t i s t i c V a l u e U n i t Monthly Flow Statistics Flow Report [Low Flow Region 3 2008 5065] S t a t i s t i c V a l u e U n i t Monthly Flow Statistics Citations USGS Data Disclaimer : Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or 7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/10/11 implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. USGS Software Disclaimer: This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use. USGS Product Names Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Application Version: 4.21.0 StreamStats Services Version: 1.2.22 NSS Services Version: 2.2.1 7/21/24, 12:56 PM StreamStats https://streamstats.usgs.gov/ss/11/11 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 24 cv middle basin undeveloped Hydrograph type = Rational Peak discharge = 147.69 cfs Storm frequency = 2 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 265,846 cuft Drainage area = 96.000 ac Runoff coeff. = 0.55 Intensity = 2.797 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 1 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 20.00 20.00 40.00 40.00 60.00 60.00 80.00 80.00 100.00 100.00 120.00 120.00 140.00 140.00 160.00 160.00 Q (cfs) Time (min) cv middle basin undeveloped Hyd. No. 24 -- 2 Year Hyd No. 24 Exhibit 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 24 cv middle basin undeveloped Hydrograph type = Rational Peak discharge = 200.96 cfs Storm frequency = 10 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 361,731 cuft Drainage area = 96.000 ac Runoff coeff. = 0.55 Intensity = 3.806 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 2 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 30.00 30.00 60.00 60.00 90.00 90.00 120.00 120.00 150.00 150.00 180.00 180.00 210.00 210.00 Q (cfs) Time (min) cv middle basin undeveloped Hyd. No. 24 -- 10 Year Hyd No. 24 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 24 cv middle basin undeveloped Hydrograph type = Rational Peak discharge = 237.60 cfs Storm frequency = 25 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 427,680 cuft Drainage area = 96.000 ac Runoff coeff. = 0.55 Intensity = 4.500 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 3 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 30.00 30.00 60.00 60.00 90.00 90.00 120.00 120.00 150.00 150.00 180.00 180.00 210.00 210.00 240.00 240.00 Q (cfs) Time (min) cv middle basin undeveloped Hyd. No. 24 -- 25 Year Hyd No. 24 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 24 cv middle basin undeveloped Hydrograph type = Rational Peak discharge = 264.00 cfs Storm frequency = 50 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 475,200 cuft Drainage area = 96.000 ac Runoff coeff. = 0.55 Intensity = 5.000 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 4 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 40.00 40.00 80.00 80.00 120.00 120.00 160.00 160.00 200.00 200.00 240.00 240.00 280.00 280.00 Q (cfs) Time (min) cv middle basin undeveloped Hyd. No. 24 -- 50 Year Hyd No. 24 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 24 cv middle basin undeveloped Hydrograph type = Rational Peak discharge = 290.40 cfs Storm frequency = 100 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 522,720 cuft Drainage area = 96.000 ac Runoff coeff. = 0.55 Intensity = 5.500 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 5 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 40.00 40.00 80.00 80.00 120.00 120.00 160.00 160.00 200.00 200.00 240.00 240.00 280.00 280.00 320.00 320.00 Q (cfs) Time (min) cv middle basin undeveloped Hyd. No. 24 -- 100 Year Hyd No. 24 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 18 cv 36 middle basin devel Hydrograph type = Rational Peak discharge = 150.38 cfs Storm frequency = 2 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 270,680 cuft Drainage area = 96.000 ac Runoff coeff. = 0.56* Intensity = 2.797 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 * Composite (Area/C) = [(22.000 x 0.60) + (74.000 x 0.55)] / 96.000 1 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 20.00 20.00 40.00 40.00 60.00 60.00 80.00 80.00 100.00 100.00 120.00 120.00 140.00 140.00 160.00 160.00 Q (cfs) Time (min) cv 36 middle basin devel Hyd. No. 18 -- 2 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 18 cv 36 middle basin devel Hydrograph type = Rational Peak discharge = 204.62 cfs Storm frequency = 10 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 368,308 cuft Drainage area = 96.000 ac Runoff coeff. = 0.56* Intensity = 3.806 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 * Composite (Area/C) = [(22.000 x 0.60) + (74.000 x 0.55)] / 96.000 2 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 30.00 30.00 60.00 60.00 90.00 90.00 120.00 120.00 150.00 150.00 180.00 180.00 210.00 210.00 Q (cfs) Time (min) cv 36 middle basin devel Hyd. No. 18 -- 10 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 18 cv 36 middle basin devel Hydrograph type = Rational Peak discharge = 241.92 cfs Storm frequency = 25 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 435,456 cuft Drainage area = 96.000 ac Runoff coeff. = 0.56* Intensity = 4.500 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 * Composite (Area/C) = [(22.000 x 0.60) + (74.000 x 0.55)] / 96.000 3 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 40.00 40.00 80.00 80.00 120.00 120.00 160.00 160.00 200.00 200.00 240.00 240.00 280.00 280.00 Q (cfs) Time (min) cv 36 middle basin devel Hyd. No. 18 -- 25 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 18 cv 36 middle basin devel Hydrograph type = Rational Peak discharge = 268.80 cfs Storm frequency = 50 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 483,840 cuft Drainage area = 96.000 ac Runoff coeff. = 0.56* Intensity = 5.000 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 * Composite (Area/C) = [(22.000 x 0.60) + (74.000 x 0.55)] / 96.000 4 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 40.00 40.00 80.00 80.00 120.00 120.00 160.00 160.00 200.00 200.00 240.00 240.00 280.00 280.00 Q (cfs) Time (min) cv 36 middle basin devel Hyd. No. 18 -- 50 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2025 Sunday, 07 / 21 / 2024 Hyd. No. 18 cv 36 middle basin devel Hydrograph type = Rational Peak discharge = 295.68 cfs Storm frequency = 100 yrs Time to peak = 30 min Time interval = 1 min Hyd. volume = 532,224 cuft Drainage area = 96.000 ac Runoff coeff. = 0.56* Intensity = 5.500 in/hr Tc by User = 30.00 min IDF Curve = City of Little Rock.IDF Asc/Rec limb fact = 1/1 * Composite (Area/C) = [(22.000 x 0.60) + (74.000 x 0.55)] / 96.000 5 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 40.00 40.00 80.00 80.00 120.00 120.00 160.00 160.00 200.00 200.00 240.00 240.00 280.00 280.00 320.00 320.00 Q (cfs) Time (min) cv 36 middle basin devel Hyd. No. 18 -- 100 Year Hyd No. 18 M:\2023\Chenal Valley 36\PREL PLAT\PREL PLAT.dwg, 7/22/2024 2:21:47 PM, bliu, White-Daters & Associates, Inc. Exhibit 6