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Home My WebLink About03 - Buxton - AppD-Attachment3I_1»4I101Kif01 ATTACHMENT 3 Compaction Results Year 1 (2018) and Year 2 (2019) after 2017-2018 Project Completion Coastal Science & Engineering [2403M-Task 2-Appendix D] Littoral Processes Buxton, Dare County, North Carolina - THISPAGEINTENTIONALLYLEFTBLANK - CSE COASTAL SCIENCE & ENGINEERING PO BOX 8056 COLUMBIA SC 29202 •TEL 803-799-89�9 • FAY\ 803-799-gd81 • W'NW.c tc I',( ien(:e.c: Y) 1/ 1/O"EM1011/ DATE: March 2, 2018 TO: Raleigh Bland (USACE) cc: Robert Outten (Dare County Manager) FROM: Drew Giles (CSE Senior Technical Associate) Haiqing Kaczkowski, PE (CSE Project Engineer) RE: 2017-2018 Beach Restoration to Protect NC Highway 12 at Buxton, Dare County, NC [CSE 2403—Task 7—Post Project Compaction Testing] Post -Project (February 2018) Sediment Compaction Results (Permit ID SAW 2015-01612) As per the USACE Special Conditions (Permit ID SAW 2015-01612) and the Biological Opinion (USFWS Log No. 04EN2000-2016-F-0060 dated 8 February 2016), Terms and Conditions — Sea Turtles, Condition #13, sediment compaction tests are required (following completion of the nourishment project) after each sand placement event. In the event the USACE and USFWS deems it necessary, the contractor shall conduct tilling/disking of the compacted beach fill area prior to 1 May to reduce the likelihood of impacting sea turtle nesting and hatching activities. Dredging and placement of sand for the Buxton beach nourishment project was successfully completed between 22 June 2017 and 27 February 2018. The project totals "2.9 miles of shoreline beginning just north of the Old Cape Hatteras Light site (project station 1925+00) and proceeding north—15,500 feet through the Cape Hatteras National Seashore to mile post 59.5 (project station 1770+50) as illustrated in Figure 1. The immediate post -nourishment sediment compaction readings were taken by Coastal Science & Engineering (CSE) on 28 February 2018. Readings were made using a digital static cone penetrometer (Humboldt SA-1510). Compaction sampling stations were located at 500-foot (ft) intervals along the nourishment area from project station 1770+00 to project station 1925+00 at two measurement locations: 1) At the seaward edge of the dune line —referred as Dune or D. 2) At the middle of the dry -sand beach —referred as Berm or B. Eight (8) additional stations were located along adjacent, unnourished sections of beach to provide a comparison with nourished areas. At each measurement location, readings were taken three times (three replicates) with a cone penetrometer at 6 inches, 12 inches, and 18 inches. A total of 40 stations were monitored with a total of 720 readings collected during this initial post project survey. Sediment compaction tests will be repeated in spring 2019 as required by the USFWS Biological Opinion unless waived by the USFWS and USACE. Mr. Raleigh Bland, USACE March 2, 2018 Cos RE: Buxton Beach Restoration - Post Project Sediment Compaction Results (Feb 2018) [2403] Page 2 N:590760 _ t E: 3032750 Mile 58 b - 0 3,000 N �.�1. 9700+00 Scale (Feet) Mlle$9 a � 1750+00 o � r fIl a+ o � c U � Mile 60 W ! 18�Qi �Q a x ai Zf 7 NC 1770+50 - RPA HI-18-004 m RPA HI-18-005 U Mile 61 q N 572780 I E:3032750 U!la9e ,g"on Buxton_ Mile 62 j Old Cape Hatteras Light Site .! C ev ECD U t o d O urn _'_ Ln o Z m � N CD O s� F— O Z a` Cape Hatteras Light . t p950 _i_ _ N:554760 t E:3032750 Cape Hatteras N:590760 E:3051750 Q N 572780 E 3051750 sed Borrow Area 0 ft x 2,300 ft (-450 ac) itional Search Area ment Borings _ N: 554760 E:3051750 Datum: SPCS NAD'83 (Feet) NC Zone 3200 FIGURE 1. Buxton (NC) project limit and borrow area. The two red zones along the project area represent the pre -nesting resource protection areas that NPS has established for the 2018 season. Both protection areas will be installed on or before 15 March 2018 and will not be allowed to be disturbed. Mr. Raleigh Bland, USACE March 2, 2018 ON (ii hS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 3 In cases where sand was too dense or prevented penetration to the appropriate depth, a value of 1,000 was given for the trial (upper limit of instrument capability). The triplicate measurements were averaged for each depth and location, and these averaged measurements were averaged again at all nourished stations and all unnourished stations (respectively). Compaction Results for 28 February 2018 Condition Attachment 1 lists the raw and averaged results from the February 2018 samples. Attachment 2 plots the averaged results along the beach at the toe of dune and at the middle of berm for the nourished area and the unnourished area (native beach). Table 1 lists the averaged results for each depth at the two locations on the beach. Figures 2 and 3 illustrate the compaction distribution along the nourished beach for all three depths at both the toe of dune and the middle of berm, and Figures 4 and 5 illustrate the results for the unnourished beach. TABLE 1. Averaged compaction results for Buxton (NC) measured 28 February 2018 (units: pound per square inch or psi). Location Seaward Edge of Dune Line Middle of the Dry -Sand Beach 6 in 12 in 18 in 6 in 12 in 18 in Nourished Beach 116 377 575 108 465 734 Un-Nourished Beach 141 469 715 128 342 596 The results show that compaction increases with depth and is generally lower at the toe of dune than along the middle of the dry -sand beach. All measurements at the 6-inch depth were well under the 500 psi threshold. At the 12-inch depth, the toe of dune measurements yielded average values of 377 psi along the nourished beach versus 469 psi along the unnourished stations. Toe of dune measurements at the 18-inch depth averages 575 psi versus 715 psi along the nourished and unnourished stations (respectively). In other words, the compaction readings at the toe of dune along the nourished area at all three depths were lower than the unnourished (control) stations at the same depths. Measurements at the middle of the dry -sand beach (berm) were higher along the nourished beach than the unnourished stations. At the 12-inch depth, nourished stations averaged 465 psi versus 342 psi at unnourished stations, both lower than the 500 psi threshold. At the 18-inch depth, nourished stations averaged 734 psi versus 596 psi at un-nourished stations, both higher than the 500 psi threshold. Mr. Raleigh Bland, USACE March 2, 2018 COS E RE: Buxton Beach Restoration - Post Project Sediment Compaction Results (Feb 2018) [24031 Page 4 Buxton Project Area - Dune Compaction Values (Feb 2018) ■ 6" -Dune ♦ 12" - Dune • 18" - Dune —500 PSI 1000 , , 900 -; t i i i I 'r - -I i--- 800 -L----[--------- --- --- --- ---- --- ---- --- --- --- --- --- --- --- --- -- f -- y700 _;____;____;_ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ _______#___; ___ ___; ___ f a ! ! . ! i i 600 ----------------- ------------ --- ---- --- ---- --- --- --- --- --- ---- --- --- --- --- --- --- --- --- ---- --- --- ---- C E 500 0 j t ! ' 400 -[ � -- - - ------ -- - -- r- [ ---- ------ --- --- ------- --- --- --- --- ---r--- --- j- --- --- --- ---1-- E 4 w300 - ---- - ---1-- 1 - --------1---J--- -------+--- --- ---- --- --- - -- --- --- --- --- --- --- --- --- ---- --- • ' 200 _ 4---- }---- i---- i---- i---- i_---- F____F___---- t ---- i---- ---- ---- i_---- F___*____' t ---- i---- i---- i_____ • . I . I 100 -- [---* +_4-- i i - -* -� - -- -- -- -- -- -- -* • � '--�- r i 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O o + + o A 0 + 0 0 0 0 0 + + + + + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 + + + + + + + + + + + + + + + + + + 0 0 0 0 0 0 + + + + + + o %o o �n Stations�� FIGURE 2. Buxton post -nourishment compaction test results along the nourished beach at the toe of the dune between stations 1770+00 and 1925+00. 1000 900 800 a 700 c .0 600 m 0- E 500 0 U 400 E d 300 PON 100 0 Buxton Project Area - Berm Compaction Values (Feb 2018) ■ 6" - Dune ♦ 12" -Dune 18" - Dune —500 PSI 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + o+ �o+ O 'Lo !� %o I-- ti-0 a0 m m CD CD N N C) CJ V V ICJ ICJ cD cD I-- r-- -0 N m m O O N N � � � � � � � � � � � � � � � � � � � � � � � � m m m m m m Stations FIGURE 3. Buxton post -nourishment compaction test results along the nourished beach at the berm between stations 1770+00 and 1925+00. Mr. Raleigh Bland, USACE March 2, 2018 ON (ii hS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 5 Control Area - Dune Compaction Values (Feb 2018) ❑ 6" - Dune 0 12" - Dune 18" - Dune —500 PSI 1000 900--------- [--------- j---------- ------------------- j--------- ?--------- [--------- j------------------------- --------- &--------[---------j--------- b 800 i-------- --------tr-------- ----------r--------- +--------- ----------r--------- ----------------- ----------------- --------- Q 700 ---------- --------- ------------------ ----------------- --------------------------------- ---------------- 0 -------- -- c d r600--------- r--------- -------- L---------1--------- --------- 1----------------- Q -------------------------------- E 500 0 t> 400 ---------- -r-------------------- T--------- -------- --------------------------------- ----------------- -------- -- E 4 d 300--------- t--------- J---------- --------- --------- J---------- --------- -------- ---------------------------------- ----------------- --------- 4 4 4 100 Q T T -------------------------- ------------------ --------- 4 0 0 0 0 0 0 0 0 0 T r r r Stations T r r r FIGURE 4. Buxton post -nourishment compaction test results along the un-nourished beach at the toe of the dune between stations 1750+00 to 1765+00 and 1930+00 to 1945+00. Control Area - Berm Compaction Values (Feb 2018) — 6"-Dune 12"-Dune 18"-Dune —500PSI 1000 900 800 c 700 c 600 U R Q E 500 0 c.> 400 E d 300 200 100 0 Stations FIGURE S. Buxton post -nourishment compaction test results along the un-nourished beach at the berm between stations 1750+00 to 1765+00 and 1930+00 to 1945+00. Mr. Raleigh Bland, USACE March 2, 2018 ON (ii hS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 6 Conclusions CSE conducted the immediate post -nourishment compaction tests on 28 February 2018 as required by the USFWS Biological Opinion (dated 8 February 2016). During this survey, a total of 720 readings were made. The results indicate the average sediment compaction at the toe of dune (where most sea turtle nests were discovered according to past records) meets USFWS 500 psi criterion for not tilling, but the average compaction at the berm along both the nourished and unnourished beach at the 18-inch depth exceeds the 500 psi criterion. The results are summarized as follows: 1) The native beach had higher compaction values (on average) than the project area at all depth intervals along the toe of the dune where most turtle nests are located. 2) The average compaction at the 6-inch and 12-inch depth intervals along the berm in the nourished beach and the native beach fall below the 500 psi criterion. At the 18-inch depth, the average compaction for the berm at both the nourished and native beach are above the 500 psi criterion (734 psi nourished and 596 psi unnourished). As the Project Engineer who designed this project, supervised the construction, and conducted the immediate post -project compaction testing, CSE requests no tilling of the beach this year based on the following: 1) Similar compaction measurements and patterns exist along the nourished and unnourished beach. 2) The beach compaction measurements are very similar to the results recorded following the Nags Head nourishment project in 2011. USACE and USFWS did not require tilling at that time. Table 2 lists the average results for Nags Head at the same season of year in both the nourished and unnourished sections following the completion of nourishment. 3) No later than 15 March 2018, NPS will be installing two pre -nesting resource protection areas (RPA) for the 2018 nesting season. Both of these protection areas (RPA HI-18-004 and RPA HI-18-005) lie within the project area. Those areas are illustrated in Figure 1 and not be allowed to be disturbed once established. TABLE 2. Averaged compaction results for Nags Head (NC) measured between 8 and 9 March 2012 (units: pound per square inch or psi). Location Seaward Edge of Dune Line Middle of the Dry -Sand Beach 6 in 12 in 18 in 6 in 12 in 18 in Nourished Beach 193 354 494 192 534 827 Un-Nourished Beach 208 500 667 188 448 698 Mr. Raleigh Bland, USACE March 2, 2018 ON (ii hS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 7 Attachment 1) Buxton Compaction Results Measured on 28 February 2018. Buxton Compaction Measurements (February 2018) - Nourished Beach D= Seaward edge of dune/structure Dune measurements were taken at seaward edge of sand fencing, where present. B=Middle of berm Units are Pounds per square inch (PS1) Measurement taken February 282018 Station Sample 6" 12" 18" 6" 1 12" 1 18" Sample 6" 12" 1 18" 6" 12" 18'. Averages Averages 1925+00 D 128 427 669 152 493 664 B 100 441 683 128 413 612 114 441 626 114 341 512 213 612 697 171 455 640 1920+00 D 128 441 654 128 1 427 631 B 100 427 711 138 398 716 114 427 626 128 356 683 142 413 612 185 413 754 1915+00 D 57 256 427 62 237 469 B 128 498 740 95 484 801 43 242 597 71 512 825 85 213 384 85 441 839 1910+00 D 185 569 740 185 503 692 B 128 455 1000 138 465 855 213 370 583 114 498 740 156 569 754 171 441 825 1905+00 D 14 555 1000 62 669 1000 B 128 384 711 119 346 744 142 782 1000 114 299 839 28 669 1000 114 356 683 1900+00 D 57 256 697 76 251 725 B 114 469 1000 85 441 817 71 242 740 100 469 754 100 256 740 43 384 697 1895+00 D 128 512 697 114 450 664 B 57 313 1 654 66 341 721 100 398 626 85 384 1 740 114 441 669 57 327 1 768 1890+00 D 100 1 484 725 85 431 711 B 43 228 640 52 218 631 85 441 683 57 213 626 71 370 725 57 213 626 1885+00 D 114 768 1000 147 702 1000 B 71 327 768 66 294 749 242 697 1000 57 256 711 85 640 1000 71 299 768 1880+00 D 185 541 1000 190 1 531 831 B 213 811 1000 303 937 1000 213 541 711 398 1000 1000 171 512 782 299 1000 1000 1875+00 D 71 1 341 669 Ir 1 152 503 798 B 156 711 1000 199 759 1000 100 455 725 228 768 1000 284 711 1000 213 797 1000 1870+00 D 171 413 455 Ir 171 1 322 474 B 100 512 882 109 569 926 128 256 455 100 555 896 213 299 512 128 640 1000 1865+00 D 199 498 541 228 460 522 B 85 398 754 104 398 740 213 427 398 114 413 711 270 455 626 114 384 754 1860+00 D 28 199 398 43 190 417 1 B 413 711 1000 360 763 1000 14 185 455 356 797 1 1000 85 185 398 313 782 1000 1855+00 D 43 242 555 24 1 242 569 B 1 71 384 1000 85 403 869 14 213 398 100 413 782 14 270 754 85 413 825 1850+00 D 128 469 484 152 455 560 B 71 413 797 81 413 759 156 398 583 71 427 711 171 498 612 100 1 398 1 768 Mr. Raleigh Bland, USACE March 2, 2018 ON (ii hS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 8 Attachment 1 (Continued) Buxton Compaction Measurements (February 2018) - Nourished Beach D= Seaward edge of dune/structure Dune measurements were taken at seaward edge of sand fencing, where present. B=Middle of berm Units are Pounds per square inch (PSI) Measurement taken February 28 2018 Station ISamplel 6" 1 12" 18" 6" 1 12" 1 1r Sample 6"1 12" 1 18" 6" 1 12" 18" Averages Averages 1845+00 D 114 213 256 119 275 332 B 71 356 569 81 313 555 128 313 370 85 299 541 114 299 370 85 284 555 1840+00 D 142 199 384 123 242 417 B 57 313 669 47 270 631 142 242 441 14 171 555 85 284 427 71 327 669 1835+00 D 14 142 284 38 133 275 B 28 299 484 62 356 545 57 128 284 57 413 626 43 128 256 100 356 526 1830+00 D 85 284 569 76 299 555 B 57 228 569 43 204 555 100 384 612 28 128 455 43 228 484 43 256 640 1825+00 D 57 313 512 62 232 488 B 100 356 669 85 1844 808 100 284 469 57 484 1000 28 100 484 100 4694 754 1820+00 D 57 199 526 62 242 531 B 57 242 640 57 284 730 57 256 541 43 242 768 71 270 526 71 370 782 1815+00 D 156 441 384 156 408 360 B 128 398 654 76 365 626 185 398 327 85 rl4 441 782 128 384 370 256 441 1810+00 D 100 356 284 133 356 313 B 114 498 640 100 531 721 185 356 356 85 512 782 114 356 299 100 583 740 1805+00 D 114 313 526 138 327 550 1 B 57 413 797 85 431 835 142 327 526 100 413 868 156 341 597 100 469 839 1800+00 D 114 313 313 138 327 375 B 128 597 1000 109 517 888 142 327 370 100 469 768 156 341 441 1 100 484 896 1795+00 D 156 597 441 166 545 493 B 85 413 868 76 408 888 213 441 398 57 484 1000 128 597 640 85 327 797 1790+00 D 71 284 370 100 294 417 B 71 270 640 66 284 754 85 299 469 43 284 839 142 299 413 85 1 299 782 1785+00 D 128 498 1000 109 431 904 B 57 213 441 43 237 431 100 484 1000 28 228 441 100 313 711 43 270 413 1780+00 D 142 413 626 128 398 578 B 128 427 583 175 446 427 114 455 640 185 455 455 128 327 469 213 455 242 1775+00 D 57 185 270 62 199 284 B 100 341 512 119 341 678 57 199 256 114 313 811 71 213 327 142 370 711 1770+00 D 85 455 683 138 498 789 B 171 441 484 109 417 474 185 498 683 100 413 455 142 541 1000 57 398 484 Average D - - - 109 325 479 B I - - - 83 453 659 Mr. Raleigh Bland, USACE March 2, 2018 ON (ii hS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 9 Attachment 1 (Continued) Buxton Compaction Measurements (February 2018) - Control Areas D=Seaward edge of dunelstructure Dune measurements were taken at seaward edge of sand fencing, where present. B=Middle of berm Units are Pounds per square inch (PSI) Measurement taken February 28 2018 Station Sample 1 6" 12" 18" 6" 12" 18" Sample 6" 12" 18" 6" 12" 18" Averages Averages 194500 D 85 199 413 100 199 351 B 199 270 256 180 294 270 128 171 199 199 284 242 85 228 441 142 327 313 194000 D 114 413 484 104 413 479 B 171 341 569 180 370 512 57 413 484 171 398 569 142 413 469 199 370 398 193500 D 242 484 811 256 545 793 B 185 270 597 199 284 621 242 569 1000 213 284 683 284 583 569 199 299 583 193000 D 270 740 1000 232 531 1000 B 171 398 569 152 370 503 199 469 1000 128 356 455 228 384 1000 156 356 484 176500 D 43 413 654 71 332 612 B 43 384 711 62 384 782 71 327 583 71 356 797 100 256 597 71 413 839 176000 D 156 597 1000 123 541 869 B 71 256 1000 71 303 946 128 498 797 71 341 1000 85 526 811 71 313 839 175500 D 114 597 1000 180 640 898 B 57 526 313 71 469 341 299 683 853 85 469 427 128 640 839 71 413 284 175000 D 57 469 512 62 555 721 B 142 356 797 109 261 792 57 640 797 85 284 768 71 555 853 100 142 811 Average D 141 469 715 B 128 342 596 Mr. Raleigh Bland, USACE March 2, 2018 COS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 10 Attachment 2) Buxton compaction results plotted along the beach (data measured on 28 February 2018). 00 T N r CO ■ 0 a T ----- I 1 1 I 1 1 I ------r ;---- ------------------------- I 1 1 I I 1 1 I I 1 1 I I 1 I I 1 1 I I I I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I I I I 1 1 I I I I 1 1 I 1 1 I I 1 1 I I 1 1 I I I I 1 1 I 1 i I 1 1 I ------* ; ;---- ------------------------- I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I I 1 1 I I I I I 1 1 I 1 1 I ------T------------------ r-------- T---- I 1 1 I I 1 1 I ------------ I I I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I ______+________ --------- F-------- +--- I I 1 1 I I 1 1 I I 1 1 I ------T ;---- ------------------------- I 1 1 I I 1 1 I I I I I 1 1 I 1 1 I I i i I 1 1 I I 1 1 I I 1 1 I I I I I 1 1 I I 1 1 I O 4 4 O 4 4 d7 op r-- CD 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 I I I 1 I I 1 -------1 I I 1 1 I - I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 I I I I 1 1 1 I I 1 I I I 1 I I I 1 I I 1 I I I 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 I I I 1 I I------1 1 I I 1 -------1 I I 1 1 I - I 1 1 I I 1 1 I I 1 I I I I I I I I 1 1 1 I I 1 1 I 1 1 I I 1 1 I I 1 I I I 1 I I 1 -------1 ------ I 1 1 I I 1 1 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I 1 I I I I I 1 1 I I 1 1 I I 1 1 I I 1 1 I I -------T--------;--------T------T--- 1 I I 1 1 I I 1 I I I I i I 1 I I 1 1 i i i 1 1 I I 1 1 i 1 I I 1 1 I I 1 I I 1 I I O O O 0 OLO D O O 0 (isd) uoi}agdwoo juawipaS 0 00+9N6 00+Oz64 00+9166 00+0664 00+9066 00+0064 00+9694 00+0694 00+9994 00+0994 00+9L9b 00+OL9b 00+999b 00+0996 00+9996 00+0996 00+9V96 OO+OV94 00+9N OO+OE94 00+9N8 00+0N8 00+9 G 9 � 00+0 G 9 � 00+9096 00+0096 00+96L4 00+06L4 00+99L4 00+09L4 00+9LL4 00+OLLb O ID CO Mr. Raleigh Bland, USACE March 2, 2018 COS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 11 Attachment 2 (Continued) CO W V- CD N a� ,ILL Y� as 7 O Ca E O U E i �01'! 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C N m c 0 w I I I ----------------- 1 I ------- 1 I 1 I 1 I -------------- I I 1 I 1 I i 1 i 1 I 1 I + y - i 1 I 1 I 1 I 1 I I I I 1 I 1 I 1 I 1 I I I ________1 I 1 I 1 I 1 I 1 I --------1 I 1 I 1 I 1 I 1 I 1 I 1 I 1 I 1 I 1 I --------+--------------F--------4---- 1 I 1 I I I I 1 1 I I I 1 I 1 I 1 I 1 I 1 1 1 1 I 1 I 1 I 1 I 1 I 1 I 1 I 1 I 1 I 1 I I I I ________1 I 1 --------- y---- #__t________aI ____ 1 I 1 I i i i I I 1 F-------1-------- J--4----L-------- 1---- 1 I 1 I --------1 I ---J-I--------1 L--------1---- �- - I 1 I 1 I 1 I 1 I 1 I I I I I I I I 1 I 1 I 1 1 1 I 1 I 1 I 1 I I I I I I I -------1 I I 1 I 1 I --------;-------- --------;---- 1 I 1 I I I I I I I 1 I 1 I I I I I I I --------1 I 1 I 1 I 1 I +---- ----------------- 1 I 1 I 1 I 1 I 11 I 1 I --------�- I 1 I 1 I 1 I 1 I 1 I --------1 I 1 I r------------ f---r--------�---- 1 I 1 I --------1 I 1 LL________ J_________ *_____ I I I I 1 1 1 I 1 1 I I I 1 I 1 1 i i i 1 1 I 1 1 i r 1 I 1 1 1 I 1 1 _I 1 I 1 1 1 I 1 1 I I I I 1 1 1 1 I 1 1 1 I 1 1 -------1 J I 1 1 1 I 1 1 1 I 1 1 _______1 I 1 1 I 1 -------- I--- 1 1 I 1 1 1 I 1 1 -------+--------if------ --------- +-f - 1 I 1 1 I 1 1 1 1 1 1 I 1 I 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 I 1 1 I 1 1 I I I ________- ------- 4_____ i i 1 1 i L__ I 1 1 1 I 1 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1- I 1 1 I I I I 1 1 1 -------; I 1 1 I I I 1 I 1 1 1 I 1 1 I I I I I 1 I 1 1 I I I L_ 1 I 1 1 I I I I I I -------1 I 1 1 1 I 1 1 --------------- 1 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 1 1 i i i 1 I 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 I 1 1 I I I I 1 I 1 1 1 I 1 1 I I I 1 I 1 1 -------1 I 1 1 L ---- J-------- 1------ WL_____ o a CD CD o a a o CD CD o a O 07 CO r� CD U-) N3- Cr7 C\I r (isd) uopedwoo juewipeS 0 OO+9Z64 OO+OZ64 00+M4 00+M4 00+9064 00+0064 00+9624 00+0624 00+9994 00+0994 00+9194 00+0194 00+9924 00+0924 00+9924 00+0924 OO+9ti94 c 00+Ove4 00+9N8 00+0N8 00+9Z84 OO+OZ24 00+M4 00+M4 00+9094 00+0094 00+9614 00+0614 00+9914 00+0914 00+9114 00+0114 Mr. Raleigh Bland, USACE March 2, 2018 COS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 12 Attachment 2 (Continued) CO r N 03 LL- U E 0 U as A� W 0 L 0 L) a 00 T m 0 N T u a CO I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 -----4-------- -------- ---------- 4 --- -------- ------------------ ------------- a---- 00+09L G I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 --------------------F--- -- ---4-------- f--------- ki ------ F-------- 00+ggL 4 I I I I I I I I I I I I I I I 1 1 1 1 1 1 I 1 1 1 I I I I I I I I ----;- ---- ;---------; --------;----a I I I I 1 1 1 1 1 1 ------; --------;-------- ; 1 1 1 1 1 1 1 1 ..... fl-; ---. 1 1 oO+DSL G I I I I I I I I I I I I I I I I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I I I I I I I I I I f]I1 --------4-------- 4---------- -------ZF------ 1 1 1 1 1 1 1 1 1 ---------------- T 1 1 1 Ly--1y --------- r- a----- I/�I G/l'.�� I 00+ J V L Y I I I I 1 1 1 1 1 1 1 1 N I I I I I I I I 1 1 1 1 1 1 1 1 V I I I I 1 1 1 1 ate! I I I I I I I I 1 1 1 1 1 1 1 1 CO I I I I --------------------- F-------- 4------ ----------- I I I I I I I I I I I I I I I I 1 1 1 F--------f-----a----------F------ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 00+0064 I I I I I I I I I I I I I I I I --------y---------------L-------- ---�-- I I I I I I I I I I I I 1 1 1 1 1 1 1 1 1 1 1 1 --------L-----------CS--- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 /}A 00+9� 6 I I I I I I I I I I I I I I I I I I I I I I I I I ------------------------------------------ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ------------ ;-------- T------- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 00+0V64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 07 CO r— c9 LO '�J- CO cv T (isd) uopedwoo ;uawipeS 00+9V64 Mr. Raleigh Bland, USACE March 2, 2018 COS E RE: Buxton Beach Restoration — Post Project Sediment Compaction Results (Feb 2018) [24031 Page 13 Attachment 2 (Continued) CO r Q N LL cc O V M 0- E O U E W W L Q O L O V a 00 T I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I JI IL I �] 1L 11 1 1L �y ________-------- l--------- r-------- ________-<_____F-__-G__i________-________r_Li____ I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I I I I I I I I 1 1 1 1 I I I I 1 1 1 1 II I I--------1 1 1 I I I I 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I I I I I I I I 1 1 1 1 II I I--------1 1 1 1 --------T--------y _------r--------T-------_ �______T________T ________r__�___ 1 i i i I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 f-------- -1 --------- F-------- f-------- --------F-[F----f--------------F----- i I I I I I I I I I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 II I I--------1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I I I I I I I I I 1 1 1 1 II I I--------1 1 1 1 i 1 i i I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 1 I I I I 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O Q) CO r- Q0 LO � CO CN r T (isd) uoiIoedwo:D ;uawipeS 00+09LG 00+99L4 00+09LG LIIIIWO I 00+0964 00+9H6 00+0V64 00+9V64 - THISPAGEINTENTIONALLYLEFTBLANK - CSE COASTAL SCIENCE & ENGINEERING PO COX 8056 COLUMBA SC 29202 •TEL 803-799-89�9 • FAY\ 803-799-gd81 W NW.c c ra';rcal4c ienc:e.c:orn MEMORANDUM DATE: April 15, 2019 TO: Raleigh Bland (USACE) Will Thompson (NIPS) Kathryn Matthews (USFWS) Heather Coats (NCDEQ—DCM) Matthew Godfrey (NCWRC) CC: Robert Outten (Dare County Manager) FROM: Drew Giles (CSE Senior Technical Associate) Haiqing Kaczkowski, PE (CSE Project Engineer) RE: 2017-2018 Beach Restoration to Protect NC Highway 12 at Buxton, Dare County, NC [CSE 2403 - PPM - Post Project Compaction Testing] Post -Project (March 2019) Sediment Compaction Results (Permit ID SAW 2015-01612; Major CAMA #136-15) As per the USACE Special Conditions (Permit ID SAW 2015-01612) and the Biological Opinion (USFWS Log No. 04EN2000-2016-F-0060), Terms and Conditions — Sea Turtles, Condition #13 (page 25), sediment compaction tests are required (following completion of the nourishment project) after each sand placement event and one time after project completion between October 1 and May 1. In the event the USACE and USFWS deems it necessary, the contractor shall conduct tilling/disking of the compacted beach fill area prior to 1 May to reduce the likelihood of impacting sea turtle nesting and hatching activities. Dredging and placement of sand for the Buxton beach nourishment project was successfully completed between 22 June 2017 and 27 February 2018. The project totals —2.9 miles of shoreline beginning just north of the Old Cape Hatteras Light site (project station 1925+00) and proceeding north—15,500 feet through the Cape Hatteras National Seashore to mile post 59.5 (project station 1770+50) as illustrated in Figure 1. The immediate post -nourishment sediment compaction readings were taken by Coastal Science & Engineering (CSE) on 28 February 2018, and a report was submitted on 2 March 2018 to the USACE (c/o Raleigh Bland). After reviewing the test results and discussing with NCWRC (c/o Matthew Godfrey) and NIPS (c/o Will Thompson), the USFWS along with other resource agencies recommended NO tilling of the project area (c/o Kathryn Matthews' email dated 14 March 2018). The one year post -nourishment sediment compaction readings were taken by CSE on 1 March 2019. Readings were made using a digital static cone penetrometer (Humboldt SA-1510). Compaction Mr. Raleigh Bland, USACE April 15, 2019 COS E RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 2 of 11 sampling stations were located at 500-foot (ft) intervals along the nourishment area from project station 1770+00 to project station 1925+00 at two measurement locations: 1) At the seaward edge of the dune line —referred as Dune or D. 2) At the middle of the dry -sand beach —referred as Berm or B. Eight (8) additional stations were located along adjacent, unnourished sections of beach to provide a comparison with nourished areas. At each measurement location, readings were taken three times (three replicates) with a cone penetrometer at 6 inches, 12 inches, and 18 inches. A total of 39 stations were monitored with a total of 702 readings collected during this one year post project survey. Station 1900+00 was skipped due to erosion of the berm and dune. E Y62rK Mile 58- E: 3051750 1 � 3 C00 V yN-S S-ae!Fav: a Mile 59 a 775p� � ..._ o y 1T7e•50 m � c. — e i Mile 50 O E m $ � �v§ qq � We fit. f g N-57[7fi0 N� $727fi0 _ E- 3D32M 6 N � E: 305175D • Buxton We fit _ 6 Q Old Cape Hadara5 N Light S7fe • 1 Cape Hatteras Light. . Q Revised Borrow Area 8.400 ft x 1,700 ft (300 ac) - No Work Area (-28 ac) • Sediment Borings N 554760 N: 554a _ E� 3032750 _ E 305,7W Cape Hatteras lha : W,S NAX W (F* NC Zt 32110 FIGURE 1. Buxton (NC) project limit and borrow area. Mr. Raleigh Bland, USACE April 15, 2019 ON (ii hS E RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 3 of 11 In cases where sand was too dense or prevented penetration to the appropriate depth, a value of 1,000 was given for the trial (upper limit of instrument capability). The triplicate measurements were averaged for each depth and location, and these averaged measurements were averaged again at all nourished stations and all unnourished stations (respectively). Compaction Results for Post -Project Year 1 (2019) Condition Attachment 1 lists the raw and averaged results from the March 2019 samples. Attachment 2 plots the averaged results along the beach at the toe of dune and at the middle of berm for the nourished area and the unnourished area (native beach). Table 1 lists the averaged results for each depth at the two locations on the beach. Figures 2 and 3 illustrate the compaction distribution along the nourished beach for all three depths at both the toe of dune and the middle of berm, and Figures 4 and 5 illustrate the results for the unnourished beach. TABLE 1. Averaged compaction results for Buxton (NC) measured 1 March 2019 (units: pound per square inch or psi). Location Seaward Edge of Dune Line Middle of the Dry -Sand Beach 6 in 12 in 18 in 6 in 12 in 18 in Nourished Beach 140 353 477 122 343 520 Un-Nourished Beach 126 515 705 141 415 650 The results show that compaction increases with depth and is generally higher at the toe of dune than along the middle of the dry -sand beach. All measurements at the 6-inch depth were well under the 500 psi threshold. At the 12-inch depth, the toe of dune measurements yielded average values of 353 psi along the nourished beach versus 515 psi along the unnourished stations. Toe of dune measurements at the 18-inch depth averages 477 psi versus 705 psi along the nourished and unnourished stations (respectively). In other words, the compaction readings at the toe of dune along the nourished area at the 12 and 18 in depths were lower than the unnourished (control) stations. Measurements at the middle of the dry -sand beach (berm) were also lower along the nourished beach than the unnourished stations. At the 12-inch depth, nourished stations averaged 343 psi versus 415 psi at unnourished stations, both lower than the 500 psi threshold. At the 18-inch depth, nourished stations averaged 520 psi versus 650 psi at un-nourished stations, both higher than the 500 psi threshold. Mr. Raleigh Bland, USACE April 15, 2019 Cos RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 4 of 11 Buxton Nourished Area - Dune Compaction Values (Mar 2019) ■ r-Dune • 12"-Dune IS"- Dune —500 PSI 1000 900 800 700 a 0 60C M E 500 0 U 1 40C 30C 20C -' 100 AL C 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O +� +� O L-7 O lr:] 9 9 Ln 9 (.� 9 U.+' O �I] o �. ] o iS] o In 9 Stationsr�^��^��^��^ FIGURE 2. Buxton post -nourishment compaction test results along the nourished beach at the toe of the dune between stations 1770+00 and 1925+00. 1000 900 80C c 700 c 600 0 E 500 0 d 40C E m 30C rn 200 100 0 Buxton Nourished Area - Berm Compaction Values (Mar 2019) ■ V' - Dune A 12"- Dune 18" - Dune —500 PSI 4 4 4 4 4 4 4 4 4 Q 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 O 9 P P 9 P O 9 O o o q Q 9 P 9 9 P 9 O 9 9 9 O Q Q 9 9 O O Q P Q i Q L] Q L] Q i OO l O L OO i OO l] OO 4] OO �. ] O l] O 4] O l OO i O l.0 O L ti— m m m m m m m m m m m m_ �� m m m m m m m m m m�� ,, m m -------- Stations_ --- FIGURE 3. Buxton post -nourishment compaction test results along the nourished beach at the berm between stations 1770+00 and 1925+00. Mr. Raleigh Bland, USACE April 15, 2019 COS E RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 5 of 11 1000 900 800 Q 700 600 b E 500 0 v = 400 m E d 300 200 100 O Unourished Control Area - Dune Compaction Values (Mar 2019) 6" - Dune 12" • Dune 18" • Dune —SOD PSI Y ll en O O O O en O O O � � ti ti ti ti Stations FIGURE 4. Buxton post -nourishment compaction test results along the un-nourished beach at the toe of the dune between stations 1750+00 to 1765+00 and 1930+00 to 1945+00. 1000 900 Q 700 c ,5 60C b E 50C 0 U = 40C as E d 30C 200 100 0 Unourished Control Area - Berm Compaction Values (Mar 2019) ❑ 6" - Dune 12'' • Dune H'' • Dune —5DD PSI -- 0 0 0 0 0 0 o a 0 0 0 0 0 0 0 t i o to o c o to o rn rn ti � � ti Stations FIGURE S. Buxton post -nourishment compaction test results along the un-nourished beach at the berm between stations 1750+00 to 1765+00 and 1930+00 to 1945+00. Mr. Raleigh Bland, USACE April 15, 2019 ON (ii hS E RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 6 of 11 Conclusions CSE conducted the Year 1 post -nourishment compaction tests on 1 March 2019 as required by the USFWS Biological Opinion (dated 8 February 2016). During this survey, a total of 702 readings were made. The results indicate the average sediment compaction at the toe of dune (where most sea turtle nests were discovered according to past records) meets USFWS 500 psi criterion for not tilling. The average compaction at the berm along both the nourished and unnourished beach at the 18-inch depth barely exceeds the 500 psi criterion at an average of 520 psi for the nourished sections. The results are summarized as follows: 1) The native beach had higher compaction values (on average) than the project area at all depth intervals along the toe of the dune where most turtle nests are located. 2) The average compaction at the 6-inch and 12-inch depth intervals along the berm in the nourished beach and the native beach fall below the 500 psi criterion. At the 18-inch depth, the average compaction for the berm at both the nourished and native beach are above the 500 psi criterion (520 psi nourished versus 650 psi unnourished). As the Project Engineer who designed this project, supervised the construction, and conducted the immediate and one year post -project compaction testing, CSE requests no tilling of the beach this year based on the following: 1) Similar compaction measurements and patterns exist along the nourished and unnourished beach. This was the observation last year immediately after nourishment and no tilling was required by USFWS. 2) Since the project's completion in February 2018, the beaches have experienced frequent overwash events associated with various coastal low pressure systems (Nor'easters) and Hurricane Florence in September 2018. These events have caused vast sand migration, resorting the sediments as well causing significant erosion to sections of the beach. CSE's survey from October 2018 showed sediment losses of "341,900 cubic yards ("22 cubic yards per linear foot of oceanfront) compared to the results in June 2018. Tilling, in loosening sediment, can exacerbate erosion. Due to the erosion and sand migration, CSE recommends no tilling be required as the hydraulically placed sediments have been resorted to a much less compacted state as observed last year immediately following the completion of the project. This concludes the sediment compaction tests required by the Terms and Conditions — Sea Turtles, Item #13 of the USFWS Biological Opinion dated 8 February 2016 (USFWS Log No. 04EN2000-2016-F-0060). Unless otherwise directed, CSE will not conduct sediment compaction monitoring next year (2020). Mr. Raleigh Bland, USACE April 15, 2019 Cos RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 7 of 11 Attachment 1) Buxton Compaction Results Measured on 1 March 2019. Buxton Compaction Measurements (March 2019) - Nourished Beach U= Seaward edge of dunWstructure Dune measurements were taken at seaward edge of sand fencing, where present. B=Middle of berm Units are pounds per square inch (PSI) Measurement taken March 12019 Station Sample 6" 1Y 18" 6" 12" 18" Sample 1 6" 1 1Y 18" 6" 1 12" 18" Averages Averages 1925+00 D 142 512 683 147 48-4 645 B B5 512 597 10a 427 616 114 441 612 114 413 683 1a5 493 640 1DD 3% 569 1920+00 D 114 455 626 1 133 436 659 B 156 469 697 156 422 692 142 427 683 185 3M 626 142 427 669 126 413 754 1915*00 D 10D 284 434 114 251 427 B 100 526 725 109 493 778 156 228 413 85 469 797 85 242 3M 142 434 811 1910+00 D 218 612 711 204 5" 1 702 B 156 40 1000 133 493 932 218 512 669 114 526 low 185 569 725 128 484 797 1905*00 D 71 484 10DO 119 488 918 B 43 156 3M 62 138 417 129 d554:175q4 71 156 455 156 526 71 100 1 413 1900+00 D NO DUNE B NO BERM 1995*00 D 85 10, 43 71 109 71 B 0 28 57 5 28 81 71 129 71 14 43 100 57 10. 100 0 14 85 1590+00 D 114 284 327 90 327 365 B 43 100 128 fib 161 228 57 327 3% 57 171 270 100 370 413 100 213 284 1885"0 D 85 413 3M 95 422 403 B 28 199 6M 57 242 692 1-- 427 341 71 242 6M 1-- 427 484 71 264 740 1880"0 D 142 341 583 138 337 583 B 85 142 228 85 151 251 171 284 612 100 185 270 10D M4 555 71 156 284 187540 D 10D 185 114 1 90 256 190 B 1 71 395 10D- 85 441 012 71 284 171 100 469 10Du 10D 299 284 85 455 754 1870"0 D 256 384 270 242 337 284 B 26 341 697 52 365 725 229 284 284 57 3B4 725 242 341 299 71 370 754 1855"0 D 228 313 213 204 1 308 242 1 B 128 156 413 133 204 441 213 327 242 114 213 469 171 284 270 156 242 441 186040 D 100 228 494 9D 256 507 B 597 1080 low 960 1000 1000 100 270 541 5M 1000 1000 71 27C 49B 526 1000 10A 1855"0 D 10D 185 270 81 242 327 B 57 284 270 14D 322 351 71 242 327 100 327 327 71 29E 384 142 3M 455 1850"0 D 171 413 555 1 1 185 417 526 B 85 512 669 119 493 692 228 396 526 142 469 683 156 441 498 128 498 725 Mr. Raleigh Bland, USACE April 15, 2019 Cos RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 8 of 11 Attachment 1 (Continued) Buxton Compaction Measurements (March 2019) - Nourished Beach ❑= Seaward edge of duneJstructure Dune measurements were taken at seaward edge of sand fencing, where present. B=Middle of berm Units are pounds per square inch (PSI) Measurement taken March 1 2019 Station ISamplel 6" 1 12" 18" 6" 12" 18" Sample 6" IT 18" 6- Averages Aver es 1845*00 ❑ 142 3M 496 171 3B4 474 B 199 299 49B 171 322 522 135 413 469 171 341 555 135 3M 455 142 327 512 1840*00 ❑ 171 256 313 133 289 2W B 28 256 356 66 275 346 128 299 284 100 299 341 100 313 242 71 270 341 1835+00 ❑ 284 711 1000 327 692 1OW B 71 234 6M 123 299 so 327 669 1000 114 270 612 370 697 1000 135 341 711 1830-00 ❑ 57 284 697 104 284 817 B 71 213 341 100 237 346 100 242 1000 100 270 327 156 327 754 123 228 370 1825+00 ❑ 85 427 697 119 422 721 B 35 341 1000 142 413 798 114 455 754 171 484 6M 156 334 711 171 413 1 711 1920*00 ❑ 85 270 496 95 265 503 B 100 299 469 123 332 522 100 313 541 142 370 569 100 213 469 123 327 526 1915*00 ❑ 135 228 427 213 256 474 B 57 128 341 81 142 375 242 299 526 100 156 396 213 270 469 85 142 3M 1810-00 ❑ 71 128 114 95 194 199 B 57 370 341 90 365 346 100 242 171 114 327 370 114 213 313 1 100 399 327 1805+00 ❑ 65 270 356 85 289 394 B 123 341 512 142 375 512 100 313 3M 156 334 526 71 284 413 142 396 498 1800+00 ❑ 85 299 341 95 294 413 B 123 341 512 147 375 512 128 270 427 171 1 396 569 71 313 469 142 334 455 1795+00 ❑ 100 270 327 106 275 275 B 142 356 396 171 413 417 71 2M 228 171 427 3M 128 299 270 199 455 469 1790+00 ❑ 135 427 455 171 422 560 1 B 100 396 299 139 459 322 171 427 626 156 512 284 156 413 597 156 499 3M 1785W0 ❑ 142 327 496 161 313 49B B 85 284 242 123 270 247 135 313 512 114 270 242 156 299 455 171 256 256 1760+00 ❑ 128 270 413 119 256 413 B 14 228 569 71 332 598 85 256 3B4 85 370 654 142 242 "1 114 39B 541 1775+00 ❑ 299 640 663 213 560 6M B 123 313 396 133 299 427 142 498 B12 142 327 455 199 541 669 123 256 427 1770+00 0 114 555 398 r 142 498 284 B 114 356 370 138 337 346 171 499 156 171 313 3M 142 441 299 128 341 284 Ayers e B 140 353 477 B 122 343 520 Mr. Raleigh Bland, USACE April 15, 2019 Cos RE: Buxton Beach Restoration — Post Project Compaction Results (Mar 2019) [2403-PPM] Page 9 of 11 Attachment 1 (Continued) ?019). Buxton Compaction Measurements (March 2019) - Control Areas ❑= Seaward ed g e of d u Wstructu re ❑u n e measu rements were taken at seaward edge of san d f en ci n g, wh ere present. B=Middle 0 berm Units are pounds per square inch (PSI) Measurement taken March 12019 Station Sample 1 6" 12' 18' 6' 12' 18" Sample 1 6' 12' 18" 6" 12" 18" Averages Averages 1945+aa ❑ 128 242 441 123 237 431 B 156 299 394 190 3a3 351 128 270 384 199 299 1% 114 199 469 213 313 313 194a+0 ❑ 100 441 493 109 417 493 B 185 327 563 195 379 522 142 384 541 213 413 526 85 427 441 156 396 455 1935+00 ❑ 256 469 fi83 232 493 749 B 171 299 663 213 337 664 199 526 754 228 327 612 242 484 811 242 384 697 1930+00 ❑ 213 683 low 175 716 1aaa B 142 396 07 142 398 612 171 725 tom 156 441 669 142 740 tom 128 356 569 1T55+aa ❑ 71 413 640 95 441 616 B 71 496 1000 123 526 831 85 484 640 171 597 782 128 427 569 128 494 711 175a+aa ❑ 43 494 782 4T 465 W B 43 541 754 S1 574 763 71 455 725 71 597 782 28 455 711 128 583 754 1755+aa ❑ 100 654 625 156 659 792 B 43 270 711 fit 2s2 661 142 W 797 65 242 669 228 683 754 57 213 612 1i50+00 1) 57 797 1000 71 692 922 B 57 455 754 133 56= "2 85 640 754 185 669 797 71 640 711 156 569 825 Averane ❑ 125 515 105 B 141 1 415 iiSU Sediment Compaction (psi) 4 g g g g g g g g g o 1770+00 1775+00 1790+00 17B5+00 1790+00 1795+00 ■ 1800+00 ---- v x 0 1905+00 :; 1910+00 z 0 1915+00 w 1920+00 ' 1825+00 y CL 1830+00 o u,1835+00 1 B40+00 W 0 1845+00 3 1850+00 f 0 1955+00 1960+00 1965+00 p 1970+00 C 1875+00 1880+00 w 1885+00 1890+00 1895+00 0 1900+00 �? 1905+00 1910+00 1915+00 1920400 1925+00 Sediment Compaction (psi) � 8 8 8 8 8 8 8 8 8 8 1770+00 1775+00 1IB0+00 1785+00 1790+00 1795+00 " 03 1800+00 v 0 1805+00 `° 3 1810+00 1815+00 y 1820+00 I. m 1825+00 N Q' D 1830+00 m 1835+00 1840+00 B 1845+00 N 1850+00 CD n 0 1855+00 1850+00 1855+00 0 1870+00 c 1875+00 c 1880+00 I m 18B5+00 a 1890+00 1895+00 No s 1900+00 1905+00 1910+00 1915+00 1920+00 1925+00 -M D a1 n m N m � W W v c XX— N O 0 an O 7 3 W W o a E �EL v z c o- 0 D o M � m CD o N O c _0 o o m Q o v o cQ o 3 m _0 0 n v o 0 � QrD v v C v v U c N CD O 0 N A 0 v w N o D cfl Q CD • ro — N � O N N N F" lD Mr. Raleigh Bland, USACE April 15, 2019 Cos RE: Buxton Beach Restoration —Post Project Compaction Results (Mar 2019) [2403-PPM] Page 11 of 11 Attachment 2 (Continued) Unourished Control Area - Dune Compaction Values (Mar 2019) ❑ W - Dune - U"- Dune 18"- Dune —5o0 PSI 1000 900 8o0 n 700 -- ---. --- --- --- --- --- --- -' c 0 600 m E 500 O U 400 300 20C 100 0 CD� �n C LC] c+OL.C] p LC] G Stations Unourished Control Area- Berm Compaction Values (Mar 2019) El - Dune - U"- Dune 18"- Dune —600 PSI 1000 900 800 700 a C 600 V E 500 O U 400 300 200 100 --- 0 o Q Q Q O O O O CD O O O O O O O L] o In o In 4 In o Stations