Annual report for... White Oak Creek mitigation site, Johnston County, project no. 6.408014T, TIP no. R-2000WM |
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ANNUAL REPORT FOR 2004 White Oak Creek Johnston County Project No. 6.408014T TIP No. R-2000 WM Prepared By: Office of Natural Environment & Roadside Environmental Unit North Carolina Department of Transportation December 2004 TABLE OF CONTENTS SUMMARY...................................................................................................................... 1 1.0 INTRODUCTION.................................................................................................. 2 1.1 PROJECT DESCRIPTION......................................................................... 2 1.2 PURPOSE ................................................................................................. 2 1.3 PROJECT HISTORY ................................................................................. 2 2.0 HYDROLOGY....................................................................................................... 4 2.1 SUCCESS CRITERIA................................................................................ 4 2.2 HYDROLOGIC DESCRIPTION ................................................................. 4 2.3 RESULTS OF HYDROLOGIC MONITORING........................................... 6 2.3.1 Site Data ......................................................................................... 6 2.3.2 Climatic Data................................................................................. 10 2.4 CONCLUSIONS ...................................................................................... 10 3.0 VEGETATION: WHITE OAK CREEK MITIGATION SITE ................................. 12 3.1 SUCCESS CRITERIA.............................................................................. 12 3.2 DESCRIPTION OF SPECIES.................................................................. 12 3.3 RESULTS OF VEGETATION MONITORING.......................................... 14 3.4 CONCLUSIONS ...................................................................................... 14 4.0 OVERALL CONCLUSIONS/RECOMMENDATIONS.......................................... 15 LIST OF TABLES Table 1. 2004 White Oak Creek Hydrologic Monitoring Results .............................. 7 Table 2. Vegetation Monitoring Statistics............................................................... 14 LIST OF FIGURES Figure 1. Site Location Map...................................................................................... 3 Figure 2. Monitoring Gauge Location Map................................................................ 5 Figure 3 . Monitoring Gauge Hydrologic Results........................................................ 9 Figure 4. White Oak Creek 30-70 Graph ................................................................ 11 APPENDICES APPENDIX A - GAUGE DATA GRAPHS APPENDIX B - SITE PHOTOS & PLANTING PLAN 1 SUMMARY The following report summarizes the monitoring activities that have occurred in the past year on the White Oak Creek Mitigation Site. Site construction began in January 2002 and was completed in March 2002. The site was planted in late March 2002 and replanted in December 2002. The 2004-year represents the second year of vegetation monitoring. Hydrology monitoring in 2004 represents the third year of monitoring at the site. The site must demonstrate both hydrologic and vegetation success for a minimum of five consecutive years or until the site is deemed successful. The site is monitored with thirty-eight groundwater monitoring gauges and eight vegetation plots. The 2004-year represents the third year for hydrology monitoring. Overall, twenty-six of the thirty-six (non-reference) monitoring gauges indicate saturation within 12” of the surface for greater than 12.5% of the growing season. The two reference gauges, REF- 37 and REF-38, also met the saturation criteria. Ten of the thirty-six gauges did not meet the jurisdictional success criteria for the 2004-monitoring year. The 2004 vegetation monitoring of the site revealed an average density of 375 trees per acre. This average is well above the minimum success criteria of 320 trees per acre. Per letter from the Ecosystem Enhancement Program to NCDOT dated August 25, 2004, the EEP has accepted the transfer of all off-site mitigation projects. The EEP will be responsible for fulfilling the remaining monitoring requirements and future remediation for this project. 2 1.0 INTRODUCTION 1.1 PROJECT DESCRIPTION The White Oak Creek Site is located adjacent to the west bank of White Oak Creek, immediately south of Winston Road (SR 1550) and north of Austin Pond, approximately 2.5 miles west of Clayton, NC in Johnston County. The site, totaling 50.69 acres in size, was mostly in open pastureland that was used to support horses in the past. Currently, the site has been returned to its natural condition. Construction started in January 2002 and was completed in March 2002. Planting was completed in March 2002. 1.2 PURPOSE In order to demonstrate successful mitigation, hydrologic and vegetative monitoring must be conducted for a minimum of five consecutive years. Success criteria are based on federal guidelines for wetland mitigation. These guidelines stipulate criteria for both hydrologic conditions and vegetation survival. The following report details the results of hydrologic and vegetative monitoring during the 2004-growing season at the White Oak Creek Mitigation Site. Activities in 2004 reflect the third year of hydrology monitoring and the second year for vegetation monitoring, following the restoration efforts. Included in this report are analyses of both hydrologic and vegetative monitoring results, as well as local climate conditions throughout the growing season, and site photographs. 1.3 PROJECT HISTORY January 2002- March 2002 Site Construction March 2002 Site Planted August 2002 Vegetation Monitoring (1 yr.) March – November 2002 Hydrologic Monitoring (1 yr.) December 2002 Site Replanted June 2003 Vegetation Monitoring (Restart Year 1) March – November 2003 Hydrologic Monitoring (2 yr.) June 2004 Vegetation Monitoring (2 yr.) March – November 2004 Hydrologic Monitoring (3 yr.) 3 Figure 1: Vicinity Map 4 2.0 HYDROLOGY 2.1 SUCCESS CRITERIA In accordance with federal guidelines for wetland mitigation, the success criteria for hydrology states that the area must be inundated or saturated (within 12” of the surface) by surface or groundwater for at least a consecutive 12.5% of the growing season during a normal precipitation year. Areas inundated for less than 5% of the growing season are always classified as non-wetlands. A site may be found to meet the hydrology performance criteria on the basis of comparison of monitoring data taken from the site with monitoring data taken from an established reference site approved by the Corps. The Corps retains the discretion to find that the hydrology criteria are met if such monitoring data from the mitigation site and the reference site are similar. The growing season in Johnston County begins March 26 and ends November 10. These dates correspond to a 50% probability that temperatures will not drop to 28°F or lower after March 26 and before November 10.1 The growing season is 229 days; therefore, optimum hydrology requires 12.5% of this season, or at least 29 consecutive days. Local climate must also represent average conditions for the area. 2.2 HYDROLOGIC DESCRIPTION In March of 2002, thirty-eight monitoring gauges were installed across the site (Figure 2). The automatic monitoring gauges record daily readings of groundwater depth. This represents the third full growing season that the monitoring gauges have been in place. The White Oak Creek Site was designed to receive hydrologic input from rainfall and surface water accessing the floodplain. The hydrologic monitoring should show the reaction of the groundwater level to specific rainfall events. 1 Natural Resources Conservation Service, Soil Survey of Wake County, North Carolina, p. 79. 5 6 2.3 RESULTS OF HYDROLOGIC MONITORING 2.3.1 Site Data The maximum number of consecutive days that the groundwater was within twelve inches of the surface was determined for each well. This number was converted into a percentage of the 229-day growing season (March 26 – November 10). The results are presented in Table 1. Appendix A contains a plot of the groundwater depth for each monitoring well. If the gauge shows saturation for greater than 12.5% of the growing season, the maximum number of consecutive days is noted on each graph. The individual precipitation events are shown on the monitoring well graphs as bars. Figure 3 provides a graphical representation of the hydrologic results. Gauges highlighted in blue indicate wetland hydrology for more than 12.5% of the growing season. Gauges highlighted in red show hydrology between 8% and 12.5% of the growing season, while those in green indicate hydrology between 5% and 8%. Gauges highlighted in black indicate no wetland hydrology (less than 5% of the growing season). 7 Table 1. 2004 White Oak Creek Hydrologic Monitoring Results Monitoring Well <5% 5-8% 8-12.5% >12.5% Actual % Dates Meeting Success GW-1* r 1.7 GW-2*+ r 13.5 March 26-April 25 April 27-May 10 Aug 30-Sept 26 GW-3* r 4.8 GW-4+ r 100 March 26-Nov 10 GW-5*+ r 51.7 March 26-May 14 June 15-Oct 11 GW-6 r 11.7 March 26-April 21 Aug 13-Aug 25 Aug 30-Sept 25 GW-7*+ r 13.0 March 26-April 25 April 27-May 10 Aug 30-Sept 26 GW-8* r 9.1 Sept 16-Sep 28 Oct 19-Nov 8 GW-9+ r 39.1 March 26-May 10 GW-10*+ r 29.6 March 26-June 1 June 5-July 16 GW-11*+ r 80.9 April 2-Oct 4 GW-12* r 0.9 GW-13+ r 45.2 March 26-May 28 July 30-Nov 10 GW-14*+ r 23.0 April 2-May 16 Aug 13-Oct 4 GW-15* r 0.4 GW-16*+ r 83.9 March 26-Oct 4 GW-17*+ r 50.4 March 26-July 19 GW-18+ r 45.2 March 26-May 20 May 31-July 26 GW-19 r 3.0 GW-20*+ r 22.6 March 26-May 16 June 5-June 18 GW-21* r 11.4 April 1-April 20 Aug 30-Sept 24 8 Monitoring Well <5% 5-8% 8-12.5% >12.5% Actual % Dates Meeting Success GW-22* r 20.1 March 26-May 10 GW-23*+ r 18.3 April 1-May12 Aug 30-Oct 2 GW-24* r 20.5 March 26-May 11 GW-25*+ r 32.3 March 26-May 17 July 30-Oct 11 GW-26* r 46.3 April 2-July 16 Sept 25-Nov 5 GW-27*+ r 45.0 May 31-June 22 July 30-Nov 10 GW-28*+ r 18.3 April 1-May 12 GW-29*+ r 35.8 March 26-June 15 GW-30* r 1.3 GW-31*+ r 18.3 April 1-May 12 GW-32*+ r 74.3 May 23-Nov 10 GW-33*+ r 49.1 March 26-July 16 GW-34+ r 100.0 March 26-Nov 10 GW-35+ r 44.8 March 26-May 28 July 30-Nov 10 GW-36* r 0 REF-37+ r 100 March 26-Nov 10 REF-38+ r 20.4 March 26-May 11 * Gauge experienced a malfunction during the growing season. +Gauge met the success criterion during an average rainfall month (February, April, May, July, and November). 9 10 2.3.2 Climatic Data Figure 4 represents an evaluation of the local climate in comparison with historical data in order to determine whether 2004 was “average” in terms of rainfall. The two lines represent the 30th and 70th percentiles of monthly precipitation for Clayton. The bars are the monthly rainfall totals for parts of 2003 and 2004. The onsite rain gauge experienced a gauge malfunction, therefore the rain gauge from the Clayton weather station was used for the following dates: January 1 - May 4 and July 9 - November 26. The State Climate Office collected the historical and monthly rainfall data. For the 2004-year, the month of January, March, and October recorded below average rainfall. The months of November (03’), December (03’), February, April, May, July, and November all recorded average rainfall for the site. June, August, and September all recorded above average rainfall. Overall, 2004 experienced an average rainfall year. 2.4 CONCLUSIONS Twenty-six of the thirty-six (non-reference) monitoring gauges indicated saturation within 12” of the surface for greater than 12.5% of the growing season. Three gauges resulted in saturation between 8% and 12.5% and no gauges showed saturation levels between 5% and 8%. Seven of the thirty-six gauges had saturation levels less than 5% of the growing season. Both reference gauges (REF-37 and REF-38) met the jurisdiction criteria in 2004. 11 Figure 4: 30-70 Percentile Graph White Oak Creek 30-70 Percentile Graph Clayton, NC 0 2 4 6 8 10 12 14 Nov 03' Dec 03' Jan 04' Feb 04' Mar 04' Apr 04' May 04' Jun 04' Jul 04' Aug 04' Sep 04' Oct 04' Nov 04' Dec 04' Month Precipitation (inches) 2003 Rainfall 2004 Rainfall 30th Percentile 70th Percentile 30th Percentile 70th Percentile 12 3.0 VEGETATION: WHITE OAK MITIGATION SITE (YEAR 2 MONITORING) 3.1 SUCCESS CRITERIA Success Criteria states that at least 320 stems per acre must survive after the completion of the third growing season. The required survival criterion will decrease by 10% per year after the third year of vegetation monitoring (i.e., for an expected 290 stems per acre for year 4, and 260 stems per acre for year 5.) 3.2 DESCRIPTION OF SPECIES The following tree species were planted in the Wetland Areas: Zone 1: Wetland Restoration Area (10.03 acres) Quercus lyrata, Overcup Oak Quercus michauxii, Swamp Chestnut Oak Quercus phellos, Willow Oak Quercus nigra, Water Oak Nyssa sylvatica var. biflora, Swamp Blackgum Fraxinus pennsylvanica, Green Ash Cornus amomum, Silky Dogwood Sambucus canadensis, Elderberry Cephalanthus occidentalis, Buttonbush Zone 2: Wetland Enhancement Area (1.58 acres) Quercus lyrata, Overcup Oak Quercus michauxii, Swamp Chestnut Oak Quercus phellos, Willow Oak Quercus nigra, Water Oak Nyssa sylvatica var. biflora, Swamp Blackgum Fraxinus pennsylvanica, Green Ash Cornus amomum, Silky Dogwood Sambucus canadensis, Elderberry Cephalanthus occidentalis, Buttonbush Zone 3: Wetland Creation Area (6.59 acres) 13 Quercus lyrata, Overcup Oak Quercus michauxii, Swamp Chestnut Oak Quercus phellos, Willow Oak Quercus nigra, Water Oak Nyssa sylvatica var. biflora, Swamp Blackgum Fraxinus pennsylvanica, Green Ash 14 3.3 RESULTS OF VEGETATION MONITIORING Table 2. Vegetation Monitoring Statistics Site Notes: Other species noted: ragweed, broomsedge, Scirpus sp., black willow, Juncus sp., trumpet creeper, briars, fennel, smartweed, cattails, yellow nutsedge, fescue, arrow arum, lespedeza, and various grasses. Due to heavy competition of Juncus sp. in plots 2, 3, 6, and 8 the trees were very difficult to find. Plots 3 and 8 had approximately 2 to 3 inches of standing water at time of monitoring. There were a few sweetgum noted in the front portion of the site near the road but at this time the sweetgum are not a problem. 3.4 CONCLUSIONS Of the 50.7 acres on this site, approximately 18.2 acres involved tree planting. An upland buffer area that consisted of 12.04 acres was planted. There were 8-vegetation monitoring plots established throughout the planting areas. The 2004 vegetation monitoring of the site revealed an average tree density of 375 trees per acre. This average is above the minimum success criteria of 320 trees per acre. 1 5 3 2 1 4 9 1 1 26 40 442 2 2 2 1 1 5 2 2 15 38 268 3 2 1 2 7 7 2 4 2 5 4 5 3 7 8 4 1 3 1 5 3 2 6 21 24 595 5 1 7 1 1 4 1 4 3 7 2 5 7 6 2 1 5 1 9 31 197 7 1 12 2 4 1 5 3 1 3 32 40 544 8 4 1 1 3 2 1 3 1 5 3 2 3 1 9 T o ta l D e n s ity A v e ra g e 3 7 5 15 4.0 OVERALL CONCLUSIONS/RECOMMENDATIONS The third year for hydrologic monitoring resulted in twenty-six of the thirty-six (non-reference) monitoring gauges showing saturation within 12” of the surface for greater than 12.5% of the growing season. The two reference gauges, REF-37 and REF-38, also exceeded the optimum saturation period. Ten of the thirty-six gauges did not meet the jurisdictional success criteria for the 2004-monitoring year. Due to the low stem counts after year one, the site was replanted in December 2002. The site has improved with an average density of 375 trees per acre, which is above the minimum success of 320 trees pre acre. Per letter from the Ecosystem Enhancement Program to NCDOT dated August 25, 2004, the EEP has accepted the transfer of all off-site mitigation projects. The EEP will be responsible for fulfilling the remaining monitoring requirements and future remediation for this project. APPENDIX A GAUGE DATA GRAPHS APPENDIX B SITE PHOTOS & PLANTING PLAN White Oak Creek Photo 1 Photo 2 Photo 3 Photo 4 Photo 5 Photo 6 2004
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Title | Annual report for... White Oak Creek mitigation site, Johnston County, project no. 6.408014T, TIP no. R-2000WM |
Other Title | White Oak Creek mitigation site, Johnston County |
Date | 2004-12 |
Description | 2004 |
Digital Characteristics-A | 2067 KB; 22 p. |
Digital Format | application/pdf |
Full Text | ANNUAL REPORT FOR 2004 White Oak Creek Johnston County Project No. 6.408014T TIP No. R-2000 WM Prepared By: Office of Natural Environment & Roadside Environmental Unit North Carolina Department of Transportation December 2004 TABLE OF CONTENTS SUMMARY...................................................................................................................... 1 1.0 INTRODUCTION.................................................................................................. 2 1.1 PROJECT DESCRIPTION......................................................................... 2 1.2 PURPOSE ................................................................................................. 2 1.3 PROJECT HISTORY ................................................................................. 2 2.0 HYDROLOGY....................................................................................................... 4 2.1 SUCCESS CRITERIA................................................................................ 4 2.2 HYDROLOGIC DESCRIPTION ................................................................. 4 2.3 RESULTS OF HYDROLOGIC MONITORING........................................... 6 2.3.1 Site Data ......................................................................................... 6 2.3.2 Climatic Data................................................................................. 10 2.4 CONCLUSIONS ...................................................................................... 10 3.0 VEGETATION: WHITE OAK CREEK MITIGATION SITE ................................. 12 3.1 SUCCESS CRITERIA.............................................................................. 12 3.2 DESCRIPTION OF SPECIES.................................................................. 12 3.3 RESULTS OF VEGETATION MONITORING.......................................... 14 3.4 CONCLUSIONS ...................................................................................... 14 4.0 OVERALL CONCLUSIONS/RECOMMENDATIONS.......................................... 15 LIST OF TABLES Table 1. 2004 White Oak Creek Hydrologic Monitoring Results .............................. 7 Table 2. Vegetation Monitoring Statistics............................................................... 14 LIST OF FIGURES Figure 1. Site Location Map...................................................................................... 3 Figure 2. Monitoring Gauge Location Map................................................................ 5 Figure 3 . Monitoring Gauge Hydrologic Results........................................................ 9 Figure 4. White Oak Creek 30-70 Graph ................................................................ 11 APPENDICES APPENDIX A - GAUGE DATA GRAPHS APPENDIX B - SITE PHOTOS & PLANTING PLAN 1 SUMMARY The following report summarizes the monitoring activities that have occurred in the past year on the White Oak Creek Mitigation Site. Site construction began in January 2002 and was completed in March 2002. The site was planted in late March 2002 and replanted in December 2002. The 2004-year represents the second year of vegetation monitoring. Hydrology monitoring in 2004 represents the third year of monitoring at the site. The site must demonstrate both hydrologic and vegetation success for a minimum of five consecutive years or until the site is deemed successful. The site is monitored with thirty-eight groundwater monitoring gauges and eight vegetation plots. The 2004-year represents the third year for hydrology monitoring. Overall, twenty-six of the thirty-six (non-reference) monitoring gauges indicate saturation within 12” of the surface for greater than 12.5% of the growing season. The two reference gauges, REF- 37 and REF-38, also met the saturation criteria. Ten of the thirty-six gauges did not meet the jurisdictional success criteria for the 2004-monitoring year. The 2004 vegetation monitoring of the site revealed an average density of 375 trees per acre. This average is well above the minimum success criteria of 320 trees per acre. Per letter from the Ecosystem Enhancement Program to NCDOT dated August 25, 2004, the EEP has accepted the transfer of all off-site mitigation projects. The EEP will be responsible for fulfilling the remaining monitoring requirements and future remediation for this project. 2 1.0 INTRODUCTION 1.1 PROJECT DESCRIPTION The White Oak Creek Site is located adjacent to the west bank of White Oak Creek, immediately south of Winston Road (SR 1550) and north of Austin Pond, approximately 2.5 miles west of Clayton, NC in Johnston County. The site, totaling 50.69 acres in size, was mostly in open pastureland that was used to support horses in the past. Currently, the site has been returned to its natural condition. Construction started in January 2002 and was completed in March 2002. Planting was completed in March 2002. 1.2 PURPOSE In order to demonstrate successful mitigation, hydrologic and vegetative monitoring must be conducted for a minimum of five consecutive years. Success criteria are based on federal guidelines for wetland mitigation. These guidelines stipulate criteria for both hydrologic conditions and vegetation survival. The following report details the results of hydrologic and vegetative monitoring during the 2004-growing season at the White Oak Creek Mitigation Site. Activities in 2004 reflect the third year of hydrology monitoring and the second year for vegetation monitoring, following the restoration efforts. Included in this report are analyses of both hydrologic and vegetative monitoring results, as well as local climate conditions throughout the growing season, and site photographs. 1.3 PROJECT HISTORY January 2002- March 2002 Site Construction March 2002 Site Planted August 2002 Vegetation Monitoring (1 yr.) March – November 2002 Hydrologic Monitoring (1 yr.) December 2002 Site Replanted June 2003 Vegetation Monitoring (Restart Year 1) March – November 2003 Hydrologic Monitoring (2 yr.) June 2004 Vegetation Monitoring (2 yr.) March – November 2004 Hydrologic Monitoring (3 yr.) 3 Figure 1: Vicinity Map 4 2.0 HYDROLOGY 2.1 SUCCESS CRITERIA In accordance with federal guidelines for wetland mitigation, the success criteria for hydrology states that the area must be inundated or saturated (within 12” of the surface) by surface or groundwater for at least a consecutive 12.5% of the growing season during a normal precipitation year. Areas inundated for less than 5% of the growing season are always classified as non-wetlands. A site may be found to meet the hydrology performance criteria on the basis of comparison of monitoring data taken from the site with monitoring data taken from an established reference site approved by the Corps. The Corps retains the discretion to find that the hydrology criteria are met if such monitoring data from the mitigation site and the reference site are similar. The growing season in Johnston County begins March 26 and ends November 10. These dates correspond to a 50% probability that temperatures will not drop to 28°F or lower after March 26 and before November 10.1 The growing season is 229 days; therefore, optimum hydrology requires 12.5% of this season, or at least 29 consecutive days. Local climate must also represent average conditions for the area. 2.2 HYDROLOGIC DESCRIPTION In March of 2002, thirty-eight monitoring gauges were installed across the site (Figure 2). The automatic monitoring gauges record daily readings of groundwater depth. This represents the third full growing season that the monitoring gauges have been in place. The White Oak Creek Site was designed to receive hydrologic input from rainfall and surface water accessing the floodplain. The hydrologic monitoring should show the reaction of the groundwater level to specific rainfall events. 1 Natural Resources Conservation Service, Soil Survey of Wake County, North Carolina, p. 79. 5 6 2.3 RESULTS OF HYDROLOGIC MONITORING 2.3.1 Site Data The maximum number of consecutive days that the groundwater was within twelve inches of the surface was determined for each well. This number was converted into a percentage of the 229-day growing season (March 26 – November 10). The results are presented in Table 1. Appendix A contains a plot of the groundwater depth for each monitoring well. If the gauge shows saturation for greater than 12.5% of the growing season, the maximum number of consecutive days is noted on each graph. The individual precipitation events are shown on the monitoring well graphs as bars. Figure 3 provides a graphical representation of the hydrologic results. Gauges highlighted in blue indicate wetland hydrology for more than 12.5% of the growing season. Gauges highlighted in red show hydrology between 8% and 12.5% of the growing season, while those in green indicate hydrology between 5% and 8%. Gauges highlighted in black indicate no wetland hydrology (less than 5% of the growing season). 7 Table 1. 2004 White Oak Creek Hydrologic Monitoring Results Monitoring Well <5% 5-8% 8-12.5% >12.5% Actual % Dates Meeting Success GW-1* r 1.7 GW-2*+ r 13.5 March 26-April 25 April 27-May 10 Aug 30-Sept 26 GW-3* r 4.8 GW-4+ r 100 March 26-Nov 10 GW-5*+ r 51.7 March 26-May 14 June 15-Oct 11 GW-6 r 11.7 March 26-April 21 Aug 13-Aug 25 Aug 30-Sept 25 GW-7*+ r 13.0 March 26-April 25 April 27-May 10 Aug 30-Sept 26 GW-8* r 9.1 Sept 16-Sep 28 Oct 19-Nov 8 GW-9+ r 39.1 March 26-May 10 GW-10*+ r 29.6 March 26-June 1 June 5-July 16 GW-11*+ r 80.9 April 2-Oct 4 GW-12* r 0.9 GW-13+ r 45.2 March 26-May 28 July 30-Nov 10 GW-14*+ r 23.0 April 2-May 16 Aug 13-Oct 4 GW-15* r 0.4 GW-16*+ r 83.9 March 26-Oct 4 GW-17*+ r 50.4 March 26-July 19 GW-18+ r 45.2 March 26-May 20 May 31-July 26 GW-19 r 3.0 GW-20*+ r 22.6 March 26-May 16 June 5-June 18 GW-21* r 11.4 April 1-April 20 Aug 30-Sept 24 8 Monitoring Well <5% 5-8% 8-12.5% >12.5% Actual % Dates Meeting Success GW-22* r 20.1 March 26-May 10 GW-23*+ r 18.3 April 1-May12 Aug 30-Oct 2 GW-24* r 20.5 March 26-May 11 GW-25*+ r 32.3 March 26-May 17 July 30-Oct 11 GW-26* r 46.3 April 2-July 16 Sept 25-Nov 5 GW-27*+ r 45.0 May 31-June 22 July 30-Nov 10 GW-28*+ r 18.3 April 1-May 12 GW-29*+ r 35.8 March 26-June 15 GW-30* r 1.3 GW-31*+ r 18.3 April 1-May 12 GW-32*+ r 74.3 May 23-Nov 10 GW-33*+ r 49.1 March 26-July 16 GW-34+ r 100.0 March 26-Nov 10 GW-35+ r 44.8 March 26-May 28 July 30-Nov 10 GW-36* r 0 REF-37+ r 100 March 26-Nov 10 REF-38+ r 20.4 March 26-May 11 * Gauge experienced a malfunction during the growing season. +Gauge met the success criterion during an average rainfall month (February, April, May, July, and November). 9 10 2.3.2 Climatic Data Figure 4 represents an evaluation of the local climate in comparison with historical data in order to determine whether 2004 was “average” in terms of rainfall. The two lines represent the 30th and 70th percentiles of monthly precipitation for Clayton. The bars are the monthly rainfall totals for parts of 2003 and 2004. The onsite rain gauge experienced a gauge malfunction, therefore the rain gauge from the Clayton weather station was used for the following dates: January 1 - May 4 and July 9 - November 26. The State Climate Office collected the historical and monthly rainfall data. For the 2004-year, the month of January, March, and October recorded below average rainfall. The months of November (03’), December (03’), February, April, May, July, and November all recorded average rainfall for the site. June, August, and September all recorded above average rainfall. Overall, 2004 experienced an average rainfall year. 2.4 CONCLUSIONS Twenty-six of the thirty-six (non-reference) monitoring gauges indicated saturation within 12” of the surface for greater than 12.5% of the growing season. Three gauges resulted in saturation between 8% and 12.5% and no gauges showed saturation levels between 5% and 8%. Seven of the thirty-six gauges had saturation levels less than 5% of the growing season. Both reference gauges (REF-37 and REF-38) met the jurisdiction criteria in 2004. 11 Figure 4: 30-70 Percentile Graph White Oak Creek 30-70 Percentile Graph Clayton, NC 0 2 4 6 8 10 12 14 Nov 03' Dec 03' Jan 04' Feb 04' Mar 04' Apr 04' May 04' Jun 04' Jul 04' Aug 04' Sep 04' Oct 04' Nov 04' Dec 04' Month Precipitation (inches) 2003 Rainfall 2004 Rainfall 30th Percentile 70th Percentile 30th Percentile 70th Percentile 12 3.0 VEGETATION: WHITE OAK MITIGATION SITE (YEAR 2 MONITORING) 3.1 SUCCESS CRITERIA Success Criteria states that at least 320 stems per acre must survive after the completion of the third growing season. The required survival criterion will decrease by 10% per year after the third year of vegetation monitoring (i.e., for an expected 290 stems per acre for year 4, and 260 stems per acre for year 5.) 3.2 DESCRIPTION OF SPECIES The following tree species were planted in the Wetland Areas: Zone 1: Wetland Restoration Area (10.03 acres) Quercus lyrata, Overcup Oak Quercus michauxii, Swamp Chestnut Oak Quercus phellos, Willow Oak Quercus nigra, Water Oak Nyssa sylvatica var. biflora, Swamp Blackgum Fraxinus pennsylvanica, Green Ash Cornus amomum, Silky Dogwood Sambucus canadensis, Elderberry Cephalanthus occidentalis, Buttonbush Zone 2: Wetland Enhancement Area (1.58 acres) Quercus lyrata, Overcup Oak Quercus michauxii, Swamp Chestnut Oak Quercus phellos, Willow Oak Quercus nigra, Water Oak Nyssa sylvatica var. biflora, Swamp Blackgum Fraxinus pennsylvanica, Green Ash Cornus amomum, Silky Dogwood Sambucus canadensis, Elderberry Cephalanthus occidentalis, Buttonbush Zone 3: Wetland Creation Area (6.59 acres) 13 Quercus lyrata, Overcup Oak Quercus michauxii, Swamp Chestnut Oak Quercus phellos, Willow Oak Quercus nigra, Water Oak Nyssa sylvatica var. biflora, Swamp Blackgum Fraxinus pennsylvanica, Green Ash 14 3.3 RESULTS OF VEGETATION MONITIORING Table 2. Vegetation Monitoring Statistics Site Notes: Other species noted: ragweed, broomsedge, Scirpus sp., black willow, Juncus sp., trumpet creeper, briars, fennel, smartweed, cattails, yellow nutsedge, fescue, arrow arum, lespedeza, and various grasses. Due to heavy competition of Juncus sp. in plots 2, 3, 6, and 8 the trees were very difficult to find. Plots 3 and 8 had approximately 2 to 3 inches of standing water at time of monitoring. There were a few sweetgum noted in the front portion of the site near the road but at this time the sweetgum are not a problem. 3.4 CONCLUSIONS Of the 50.7 acres on this site, approximately 18.2 acres involved tree planting. An upland buffer area that consisted of 12.04 acres was planted. There were 8-vegetation monitoring plots established throughout the planting areas. The 2004 vegetation monitoring of the site revealed an average tree density of 375 trees per acre. This average is above the minimum success criteria of 320 trees per acre. 1 5 3 2 1 4 9 1 1 26 40 442 2 2 2 1 1 5 2 2 15 38 268 3 2 1 2 7 7 2 4 2 5 4 5 3 7 8 4 1 3 1 5 3 2 6 21 24 595 5 1 7 1 1 4 1 4 3 7 2 5 7 6 2 1 5 1 9 31 197 7 1 12 2 4 1 5 3 1 3 32 40 544 8 4 1 1 3 2 1 3 1 5 3 2 3 1 9 T o ta l D e n s ity A v e ra g e 3 7 5 15 4.0 OVERALL CONCLUSIONS/RECOMMENDATIONS The third year for hydrologic monitoring resulted in twenty-six of the thirty-six (non-reference) monitoring gauges showing saturation within 12” of the surface for greater than 12.5% of the growing season. The two reference gauges, REF-37 and REF-38, also exceeded the optimum saturation period. Ten of the thirty-six gauges did not meet the jurisdictional success criteria for the 2004-monitoring year. Due to the low stem counts after year one, the site was replanted in December 2002. The site has improved with an average density of 375 trees per acre, which is above the minimum success of 320 trees pre acre. Per letter from the Ecosystem Enhancement Program to NCDOT dated August 25, 2004, the EEP has accepted the transfer of all off-site mitigation projects. The EEP will be responsible for fulfilling the remaining monitoring requirements and future remediation for this project. APPENDIX A GAUGE DATA GRAPHS APPENDIX B SITE PHOTOS & PLANTING PLAN White Oak Creek Photo 1 Photo 2 Photo 3 Photo 4 Photo 5 Photo 6 2004 |
OCLC number | 781632369 |