HomeMy WebLinkAbout20190661 Ver 1_Sassarixa Swamp Bank Winter 2023 Supplemental Planting Memo_20230127ID#* 20190661
Select Reviewer:
Katie Merritt
Initial Review Completed Date 02/01/2023
Mitigation Project Submittal - 1/27/2023
Version* 1
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Type of Mitigation Project:*
Stream Wetlands Buffer Nutrient Offset
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Project Contact Information
Contact Name:*
Jason Lorch
Project Information
ID#:* 20190661
Existing ID#
Project Type: DMS • Mitigation Bank
Project Name: Sassarixa Swamp II
County: Johnston
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Email Address:*
jlorch@wildlandseng.com
Version:* 1
Existing Version
Mitigation Document Type:*
Mitigation Remediation Plans
File Upload: Sassarixa Swamp Bank Winter 2023 Supplemental
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Planting Memo.pdf
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Print Name: * Jason Lorch
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IIVS014 C01ch
WILDLANDS
ENGINEERING
Technical Memorandum
TO: Katie Merritt
FROM: Jason Lorch
DATE: January 27, 2023
SUBJECT: Winter 2023 Supplemental Planting
Sassarixa Swamp II Nutrient Offset and Buffer Mitigation Bank Parcel
DWR Project No. 2019-0661v1
INTRODUCTION
The Sassarixa Swamp II Nutrient Offset and Buffer Mitigation Bank Parcel ("Parcel") Monitoring Year 2 (MY2)
report was submitted to the North Carolina Division of Water Resources (NCDWR) on October 17, 2022. Within
the MY2 report, a supplemental planting for Winter 2022-2023 was mentioned. Wildlands Engineering received
a request from NCDWR on January 18, 2023, to provide additional documentation on the supplemental planting.
SUPPLEMENTAL PLANTING
At the time of MY2 report submittal, Wildlands was still in the process of determining how extensive the tree
mortality was across the Parcel even though the MY2 vegetation plot data suggested otherwise. However,
following report submittal as herbaceous vegetation died back and additional site walks were conducted,
Wildlands saw signs of varying degrees of tree mortality along parts of T1, the ditch above T3, T4, T5A, and T5C
due to dry site conditions within the Parcel. Wildlands believes it is within the site's best interest to
supplementally plant this area early in the monitoring period to offset the tree mortality. A visual depiction of
the anticipated February 2023 supplemental planting can be seen in Figure 1.
It is suspected that tree mortality is due to high floodplain elevations compared to the stream portion of the
project, causing dry site conditions within the Parcel and several years of drought conditions since the original
planting. It is not believed that poor soils or species selection is the cause of tree mortality, as a result species
selected for planting were those originally approved by NCDWR in the Sassarixa Swamp II Nutrient Offset and
Buffer Mitigation Bank Parcel Development Package. Table 1 below lists species selected along with their
planted quantities and composition.
Table 1. Tree Species Selected for Supplemental Planting
Species
Common Name
Type
Stems per Species
Planting Composition
Populus deltoides
Eastern Cottonwood
Bare Root
172
7%
Magnolia virginiana
Sweetbay Magnolia
Bare Root
147
6%
Acer negundo
Box Elder
Bare Root
245
10%
Quercus nigra
Water Oak
Bare Root
172
7%
Quercus michauxii
Swamp Chestnut Oak
Bare Root
367
15%
Platanus occidentalis
Sycamore
Bare Root
490
20%
Quercus phellos
Willow Oak
Bare Root
367
15%
Betula nigra
River Birch
Bare Root
490
20%
Totals
2,450
100%
Sassarixa Swamp II Nutrient Offset and Buffer Mitigation Bank Parcel Page 1
Technical Memorandum
Due to non -uniform tree mortality across the Parcel, a range of planting densities will be implemented in the
February 2023 supplemental planting. Table 2 below lists areas selected for supplemental planting along with
the acres and planting density per acre.
Table 2. Approximate Planting Density by Area
Area
Acres
Planting Density Per Acre
UT1— Right Bank
0.75
200
UT1— Left Bank
2.16
400
UT3
1.34
250
UT4
0.96
250
UT5A
1.00
100
UT5C
2.30
300
Tota 1
8.51
---
To ensure better tree survival with the supplemental planting being executed in February 2023, Wildlands will
implement additional management actions throughout the spring. While conducting ring sprays to reduce
herbaceous competition, a root stimulator and fish emulsion will be sprayed at the base of each supplementally
planted tree in early spring. The root stimulator and fish emulsion are predicted to help retain water in dry
conditions. After the trees have had time to establish, a mixture of soil amendments will be applied at the base
of each tree in late spring or early summer.
CONCLUSION
An 8.51-acre supplemental planting will occur in February 2023. The suspected cause of widespread planted
stem fatality is dry site conditions and not poor soils or species selection. It is anticipated that new stems being
treated with root stimulator, fish emulsion, and soil amendments will have a greater chance of survival.
Throughout the remainder of the Parcel adaptive measures will be developed, or appropriate remedial actions
will be implemented if the Parcel or a specific component of the Parcel fails to achieve the success criteria
outlined in the Bank Parcel Development Package. Parcel maintenance will be performed to correct any
identified problems that have a high likelihood of affecting project success. Going forward, Wildlands will notify
DWR of any adaptive management actions needed.
Please contact me if you have any questions at (919) 851-9986 or via email at jlorch@wildlandseng.com.
Attachments:
Updated Figure 1. Monitoring Components Map
Sassarixa Swamp II Nutrient Offset and Buffer Mitigation Bank Parcel Page 2
Technical Memorandum
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