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Home My WebLink About20080868 Ver 2_Follow Up on 2019 PCS Summary_Hydrology of Small Watersheds Draining to the Pamlico River_20191105Hydrology of Small Watersheds Draining to the Pamlico River R. W. Skaggs G.M. Chescheir D.M. Amatya Objectives • To measure outflows on a continuous basis from 8 small Pamlico River watersheds • To record water table depths at specific locations on the watersheds • To measure soil properties affecting hydrology of the watersheds • To calibrate and apply computer models to characterize the hydrology of the watersheds Conclusions • Outflow mostly driven by surface runoff and shallow subsurface flow • Flow occurs when water table close to surface • Annual outflow varied between 3% and 27% of annual precipitation • Both timing and amount of outflow can be predicted with the DRAINMOD (cal.) PCS PHOPHATE PLANT SITE Huddles -Al Huddles 2 Tooley 1 Jacks 2 Jacks 1 Huddle 3 PAMLICO RIVER J� �G OnV GJ� Huddles 4 ooley 2 Watershed Areas Watershed Area, ac. Area, adj. Huddles 1 13 Huddles 2 101 Huddles 3 129 Huddles 4 115 Jacks 1 91 22 Jacks 2 36 28 Tooley 1 105 Tooley 2 58 HUDDLES CUT Huddles Huddles 2 Tooley 1 PAMLICO RIVER HUDDY GUT Manual Water Table Well Automatic Water Table Well Automatic Flow Station Huddles 4 x W a Manual Water Table Well 0 Automatic Water Table Well ■ Automatic Flow Station z�t-1- Cr W V. 1w A I M 4.1 Upstream Stage Recorder vt A Control Structure IL . AI With V-notch Weir 4 Downstream Stage Recorder ff I —Moo.rr7- 'N7 A ou. -lP 3;M 4p, dr— ml. ! f �' Y r r r. r .lam •, f �` � � •• .. / r I 1.5 1 0.5 I H 6 -0.5 CO -1 -1.5 -2 -2.5 -3 Huddles 4, PCS Phosphate, 2002 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of the year U/S-------- D/S V-Ht N 7, At I 40 r vpmr< -W.— do 4w w 4�1 K ti Sfti�m Is Tooley Creek 2, PCS Phosphate, 2002 1.5 1.0 0.5 a� 0.0 cn -0.5 -1.0 -1.5 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of Year — U/S - - - - - D/S V-HT FA 1.6 1.4 v 1.2 1 0 0.8 FL 0.6 FIVE W I Huddles Cut 1, PCS Phosphate, 2002 0 30 60 90 120 150 180 210 240 270 300 Day of Year 1.50 1.25 1.00 a� 0.75 3 0 LL 0.50 0.25 0.00 Tooley Creek 2, PCS Phosphate, 2002 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of Year i * f �fi fi _ • �. . f f J6 i rAkW 0%. •, r a *' I �� f , l � , HUDDLES CUT Huddles Huddles 2 Tooley 1 PAMLICO RIVER HUDDY GUT Manual Water Table Well Automatic Water Table Well Automatic Flow Station Huddles 4 x W a Measured Daily and Cumulative Out Flow, Huddles 2 PCS Phosphate, 2003 3 -t 14 2.5 12 • 2 - 10 � 5 0 0 5 8 LL FL 1.5 > >' 6 _� 4 C) 0.5 - ' " 2 1 A 0 30 60 90 120 150 180 210 Day of the Year • Meas-Cum Pred-Cum — Meas-Day Pred-Day 2.5 2 0 1.5 FL 1 0.5 I Measured and Predicted Daily and Cumulative Outflow, Huddles 4, PCS Phosphate, 2003 0 30 60 90 120 150 180 210 Day of the Year Meas-Day Pred-Day Meas-Cum Pred-Cum 16 14 12 0 10 FL a� 8 6 � 4 C� 2 25.0 v 20.0 C 0 15.0 C 10.0 c� 0 5.0 m Measured Daily Outflows, 2003 Huddles 1, 2, 3 and 4, PCS Site 0 30 60 90 120 150 180 210 240 Day of the year Hud 1 Hud2 - - - - - - - - Hud3 Hud4 Manual Water Table Well 0 Automatic Water Table Well ■ Automatic Flow Station z�t-1- Cr W Jacks Creek 1, PCS Phosphate, 2000 4.0 3.5 3.0 = 2.5 3 0 FL 2.0 0 1.5 1.0 0.5 0.0 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of year Meas-Day - - - - - Pred-Da — Meas-Cum Pred-Cum Jacks Creek 1, PCS Phosphate, 2001 2.5 2.0 3 1.5 0 LL T G 1.0 0.5 0.0 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of year —Meas-Da ----Pred-Da Meas-Cum —Pred-Cum 16 14 12 10 c FL m 8 >_ 3 6 E 3 U 4 2 0 10 9 8 7 3 0 6 LL m 5 R 4 E 0 3 U 2 1 0 7 6 5 _o LL 4 T 3 0 2 1 0 3 2.5 _ 2 0 LL >' 1 .5 0 1 0.5 0 Jacks Creek 2, PCS Phosphate, 2000 IIf U 12.0 10.0 LL 8.0 6.0 E 4.0 2.0 0.0 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of Year —Meas-Da -- Prod -Day —Meas-Cum—Pred•Cum Jacks Creek 2, PCS Phosphate, 2001 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of Year -Meas-Da-----Pred•Da -Meas-Cum -Pred-Cum 6.0 5.0 LL 4.0 3.0 0 3 E 2.0 U 1 .0 0.0 Manual Water Table Well 0 Automatic Water Table Well ■ Automatic Flow Station z�t-1- Cr W 7 6 5 c 3 4 0 LL 3 m G 2 1 0 0 30 2 1.5 _0 LL r 1 0 0.5 0 Jacks Creek 1 & 2, PCS Phosphate, 2000 14.0 12.0 10.0 3 8.0 LL m 6.0 f6 E 4.0 U 2.0 0.0 60 90 120 150 180 210 240 270 300 330 360 Day of Year — Meas-Day - - - - - Prod -Day — Meas-Cum Pred-Cum Jacks Creek 1 & 2, PCS Phosphate, 2001 ■ 0 30 60 90 120 150 180 210 240 270 300 330 360 Day of Year Meas-Day -- . Pred -Day -Me as -Cum -Pred-Cum 6.0 4.5 LL 3.0 3 E U 1.5 0.0 Annual Outflow from PCS Watersheds Outflow in inches H 1 H2 H3 H4 T1 T2 J 1 &2 Mean 1999 10.2 7.8 6.3* 5.6 2000 17.2 15.2 9.8* 13.5 11.3 14.5 2001 5.4 5.0 1.9* 3.0 5.2 3.8 5.2 4.6 2002 2.8 1.3 0.4* 0.6 0.7 1.6 2.0 1.5 2003 16.0 11.5 11.9 12.3 Thro june only 12.9 * Value not used in mean Annual Outflow as Related to Rainfall (In Inches) Year Rainfall Outflow Range Flow/R 1999 2000 49.7 13.3 11.3-15.2 27% 2001 35.7 4.4 3.0-5.2 12% 2002 40.4 1.2 0.6-2.0 3% 2003(6) 29.5** 11.9** 11.5-12.3 40%** Measured/Predicted Water Balance for Huddles 2 20 18 1999 I 2000 1 2001 1 2002 1 16 _r 14 Periods with soil water deficits 12 m 10 c 0 8 0 6 4 2 0 5 10 15 20 25 30 35 40 45 50 Months beginning in May 1999 - Rain PET ! Was Flow - - - Pred Flow - - - - - Pred ET 180 160 140 s 120 100 m C 80 E 60 0 V 40 0 Cumulative Measured/Predicted Water Balance for Huddles 2 2001 Rai 2002 AET Periods with soil water deficits / Predicted Flow Measured -Flow 5 10 15 20 25 30 35 40 45 50 Months beginning in May 1999 Rain PET Was Flow - - - Pred Flow - - - - - Pred ET 18 16 14 ;j 12 06 10 bm 1 6 4 2 a Annual outflow 0 2 4 6 8 10 12 14 16 18 Measured, IN. Long Term Simulations • Huddles Cut 2 • 50 Year Simulations (1951 = 2000) • Frequency Analysis of Annual Outflow 30 Z 25 0 20 15 10 = 5 Q 0 Annual Outflow Probability PCS Huddles 2 2000 0 20 40 60 80 %of Years Flow Equaled or Exceeded 2001 2002 100 Conclusions • Outflow mostly driven by surface runoff and shallow subsurface flow • Flow occurs when water table close to surface • Annual outflow varied between 3% and 27% of annual precipitation • Both timing and amount of outflow can be predicted with the DRAINMOD (cal.)