HomeMy WebLinkAbout6.4 RPCA La Porte Wetland Report (12.15.22) FINAL
Kleinfelder
2882 Prospect Park Dr, Suite 200
Rancho Cordova, CA 95670
Phone: (916) 524-1667
To: Stephanie Loucas
Vice President of Development
Renewable Properties
(415) 710-3834
Stephanie@renewprop.com
From: Andy Mieske, Regulatory Specialist; Susan Dewar, Project Manager
Date: December 15, 2022
RE: RCPA La Porte Road Solar Project Aquatic Resources Mapping
Kleinfelder herein presents the results of an aquatic resources investigation conducted
within a private land parcel (APN # 028-240-061) south of Wilson Creek in the
community of Bangor in southeastern Butte County on November 19, 2022. This
investigation located and mapped the boundaries of aquatic resources to allow for project
planning on the site. Appendix A includes photographs of representative aquatic
resources and Appendix B displays the location and extent of aquatic resources in the
survey area. The following includes a brief overview of the methods used in this site
investigation and a description of the aquatic resources identified onsite.
Methods. Senior Vegetation Ecologist and Regulatory Specialist Andy Mieske
conducted the aquatic resources investigation in the field on November 19, 2022. The
surveyor conducted the aquatic resources investigation following the routine method for
wetland delineations as described by the United States Army Corps of Engineers
(USACE) 1987 manual and supplemented as directed by the Interim Arid West
Supplement (USACE 1987, 2006). The surveyor identified water features based on the
presence of an ordinary high water mark and wetland features based on the presence of a
predominance of hydrophytic vegetation and evidence of wetland hydrology in the field.
Results. The investigation identified the following non-tidal aquatic resources displayed
on the map in Appendix B: one ephemeral channel, one unnamed intermittent channel,
four segments of a named intermittent channel (Wilson Creek), seven seasonal wetlands,
and one seasonal wetland complex. A variety of wetland and upland areas characterize
the seasonal wetland complex. This mapping identified 2.222 acres of aquatic resources
within the 57.934-acre survey area including 0.020 acre of ephemeral channel, 0.832 acre
of intermittent channel, 0.606 acre of seasonal wetland, and 0.764 acre of seasonal
wetland complex. The ephemeral channel, three seasonal wetlands in the middle of the
survey area and the seasonal wetland complex lack a surface hydrologic connection to
Stephanie Loucas
RCPA La Porte Road Solar Project
Page 2 of 2
down gradient waters. The seasonal wetland complex has been impounded by a narrow
constructed berm and lies adjacent to the down-gradient seasonal wetland, but does not
directly abut the seasonal wetland.
The seasonal wetland complex (Photo 1 in Appendix A) receives water from a white
unmapped water tank south of the survey area. A berm constructed at the northern extent
of the wetland complex impounds water. Water seeps subsurface through the berm to
support a seasonal wetland north of the seasonal wetland complex and then flows within
an unnamed intermittent channel (Photo 2 in Appendix A) within and outside the survey
area through a seasonal wetland into a named intermittent channel (Wilson Creek,
displayed in Photo 3 in Appendix A). Wilson Creek flows in a westerly direction through
two excavated basin seasonal wetlands (westernmost displayed in Photo 4 in Appendix
A) before exiting the survey area and draining into Honcut Creek, which flows into the
Feather River, a traditional navigable water.
The southern extent of the ephemeral channel begins at the base of a slope-stabilizing
wall of coarse angular rock. The ephemeral channel (Photo 5 in Appendix A) has a
defined bed and bank and ordinary high water mark, evidenced by sediment transport.
This ephemeral channel conveys water during and immediately following storm events
over a slope with a 20 percent gradient but dissipates and lacks definition and evidence of
sediment transport as the slope gradient flattens before reaching Wilson Creek.
The three isolated seasonal wetlands in the middle of the survey area (southernmost
displayed in Photo 6 in Appendix A) have been created by excavating the land surface to
a depth close enough to the seasonal water table, and constructing berms along the lower
edges of the excavations, to create an aquic moisture regime upslope of the berms within
the upper 12 inches of the soil profile for a sufficient period during the growing season to
support a predominance of hydrophytes.
References Cited
U.S. Army Corps of Engineers (USACE) 1987. Corps of engineer’s wetlands delineation
manual. Technical Report Y-87-1. U.S. Army Engineers Waterways Experiment
Station, Vicksburg, MS. 100 pp. plus appendices.
U.S. Army Corps of Engineers (USACE) 2006. Interim Regional Supplement to the
Corps of Engineers Wetland Delineation Manual: Arid West Region. ERDC/ EL
TR-06-16. U.S. Army Corps of Engineers Research and Development Center,
Vicksburg, MS.
Appendix A
Site Photographs (November 19, 2022)
Photo 1 Impounded seasonal wetland complex receiving water from water tank
Photo 2 Intermittent channel conveying flow from uphill seasonal wetland to
seasonal wetland adjacent to Wilson Creek
Photo 3 Intermittent channel (Wilson Creek)
Photo 4 Facing southeast: Seasonal wetland left of culvert gate able to release
seasonal inundation through culvert beneath berm on right into
intermittent channel
Photo 5 Facing southeast: northern extent of isolated ephemeral channel
Photo 6 Isolated seasonal wetland excavated in middle of survey area
(southernmost of the three hydrologically isolated seasonal wetlands)
Appendix B
Aquatic Resources Map
880860900840920820940800960940
940
960
980
1000
1040
1020
780La Porte RoadW ils o n C re e k
121°23'25"W121°23'30"W121°23'35"W121°23'40"W121°23'45"W121°23'50"W121°23'55"W121°24'0"W121°24'5"W121°24'10"W
39°23'55"N39°23'50"N39°23'45"N39°23'40"N39°23'35"N39°23'30"NAquatic Resources
RCPA La PorteRoad Solar ProjectDecember 2022
Client Contact: Stephanie Loucas/415-710-3834Prepared by: Kleinfelder/916-366-1701Delineated by: Andy MieskeDelineation Survey Date: 11/19/2022Drawn By: Joseph Hiatt
USGS 7.5' Quad: Bangor (1994)PLSS: Section 22, 27; Township: 18N; Range: 05E
Notes:1. Acreage shown for each class refers to the entire delineation area.2. Feature label key provided below.3. ESRI World Imagery (9/7/2022)4. Projection: UTM Nad 83 Z10N5. Vertical datum NAVD886. Topographic elevation in feet
Legend
Survey Area (57.934 ac.)
Seasonal Wetland (0.606 ac.)
Seasonal Wetland Complex(0.764 ac.)
Culvert Gate
Ephemeral Channel (0.020 ac.)
Intermittent Channel (0.832 ac.)
Culvert
20-foot Contour
1 inch = 300 feet
Last Saved By: JHiatt Document Path: \\azrgisstorp01\GIS_Projects\Client\GANDA\Renewable_Properties\20232542_RPCA_LaPorte_Solar\LaPorte_Solar_Aquatic_Resources.mxd0 150 300Feet
±
c
c Direction of Flow