May 11, 2022
Christian Murdock, ACICP
Deputy Director of Planning
City of Pacifica, Planning Department
540 Crespi Drive
Pacifica, CA 94044
Re: 570 Crespi Drive Development Proposal
Response to Peer Review of Wetland Clarification Letter Dear Christian:
This letter responds to questions and comments in the peer review of my recent memo to you dated April 8, 2022, concerning the extent of wetlands near the southern boundary of the two parcels that comprise the project site, and in relation to the location of a proposed emergency overflow riser (i.e., drain inlet), and the City’s drainage easement located along the southern boundary. The peer review was prepared by Madrone Ecological Consulting and raised three key points:
1. Wetland delineation data forms. The requested data forms are attached. The technical information that supports my conclusions in the memo also are included in the data forms, but the data forms also include additional details mentioned in the peer review, such as percent cover of each plant species, percent of the soil colors in each soil slayer, and information on the hydrology for all three data points.
2. Equipment used to establish the wetland boundary. The location of the wetland boundary line, wetland delineation sample points, and backyard fence line shown on Sheet A-1.14 were determined in the field by measuring tape and compass using the corner post of the City’s cyclone fence enclosing the Wet-Weather Equalization Basin as a known reference point. These actual dimensions and bearings were provided to the project architect and rendered at scale in CAD.
Because of the small scale of the survey area and the dense vegetation canopy, this was as accurate as sub-meter GIS for establishing the location of the sample points and resultant boundary line in relation to the proposed riser location.
3. Map contents. The map was prepared in response to your request for more detailed information regarding the riser’s location in relation to potentially jurisdictional wetlands. Immediately following a conference call with the applicant and architect on April 1, 2022, you and I spoke further about your needs and my proposed approach to resolve these questions. I believe we agreed on the map that was prepared and submitted, focusing on the southwest corner of the property where the riser was proposed, and specifically showing the relation of the riser to the more refined wetland boundary.
If you have any questions regarding this matter, please call me at (415) 254-4835.
WOOD BIOLOGICAL CONSULTING
P.O. Box 1569
El Granada, CA 94018
[email protected]
www.wood-biological.com
Wood Biological Consulting
2 Sincerely,
Chris Rogers
cc: Brendan Murphy, Eamon Murphy, Stuart Welte
Applicant/Owner: State:
Investigator(s):
Landform (hillside, terrace, etc.): <1
Subregion (LRR): Lat:
Soil Map Unit Name:
X
Are Vegetation , Soil , or Hydrology Are “Normal Circumstances” present? Yes X No Are Vegetation , Soil , or Hydrology
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Yes No X
Yes No X Yes X
Yes No X
)
1. 2. (A)
3. 4. (B)
Sapling/Shrub Stratum (A/B)
1. 2.
3. 4. x 1 =
5. x 2 =
x 3 =
x 4 =
1. x 5 =
2. Column Totals: (A) (B)
3. 4.
5. 6.
7. 8.
9. 10.
11. Woody Vine Stratum
1. 2.
Yes X
Non-hydric vegetation dominates sample location. Arroyo willow (Salix lasiolepis; FACW) extend over sample point from plants rooted in area mapped as wetland.
Percent of Dominant Species That
Are OBL, FACW, or FAC:
5 Total Number of Dominant Species
Across All Strata:
Dominance Test worksheet:
% Bare Ground in Herb Stratum
Absolute
% Cover
Yes
265
305
53 68
=Total Cover
Rubus ursinus
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
(Plot size:
Myoporum laetum
Salix lasiolepis
Yes
=Total Cover
1 2 No
Project/Site: 570 Crespi Drive
LRR A, MLRA 4B
NWI classification:
Dominant
Species?
60 50
10 UPL
37.595511
UPL
Hydrophytic Vegetation Present?
-122.500189 Datum:
Urban Land-Orthents, cut and fill complex 0-5% slopes none Long:
2m
Are climatic / hydrologic conditions on the site typical for this time of year? No S10 T4S R6W
CA SP-1
concave
Section, Township, Range:
0.0%
)
2m )
Phoenix canariensis
Prevalence Index worksheet:
0 0
Sampling Date:
Sampling Point:
Local relief (concave, convex, none): Slope (%):
4/4/2022
Brendan and Eamon Murphy
Chris Rogers
terrace
City/County: Pacifica / San Mateo
10 Total % Cover of:
=Total Cover
1 - Rapid Test for Hydrophytic Vegetation
20 Multiply by:
20 Prevalence Index = B/A =
0 No
3 - Prevalence Index is ≤3.01
Hydrophytic Vegetation Indicators:
UPL species
FACW species
Problematic Hydrophytic Vegetation1
(Explain)
98 5 - Wetland Non-Vascular Plants1
4 - Morphological Adaptations1(Provide supporting
=Total Cover
)
Hydrophytic
Vegetation
Present? No
data in Remarks or on a separate sheet)
(Plot size:
Remarks:
5 FACU species
FAC species
OBL species
FACU
4.49 2 - Dominance Test is >50%
(If no, explain in Remarks.)
Hydric Soil Present?
Wetland Hydrology Present?
2m
naturally problematic? (If needed, explain any answers in Remarks.) (Plot size:
Yes
Number of Dominant Species That
FACW Are OBL, FACW, or FAC:
significantly disturbed?
No criteria are met.
Indicator
Status
0 2
VEGETATION – Use scientific names of plants.
(Plot size:
1 UPL
Herb Stratum
Oxalis pes-caprae
0 U.S. Army Corps of Engineers
WETLAND DETERMINATION DATA SHEET – Western Mountains, Valleys, and Coast Region See ERDC/EL TR-10-3; the proponent agency is CECW-CO-R
OMB Control #: 0710-0024, Exp: 11/30/2024
Requirement Control Symbol EXEMPT:
(Authority: AR 335-15, paragraph 5-2a)
Tree Stratum
Is the Sampled Area
within a Wetland? No
No
2 2m
5 Remarks:
ENG FORM 6116-9, JUL 2018 Western Mountains, Valleys, and Coast – Version 2.0 Sampling Point:
%% Type1 Loc2
100
100
Type:
Depth (inches): Hydric Soil Present? Yes No X
Primary Indicators (minimum of one is required; check all that apply) X
?
Surface Water Present? Yes X
Water Table Present? Yes X
Saturation Present? Yes X Wetland Hydrology Present? Yes No X
2.5 cm Mucky Peat or Peat (S2) (LRR G)
Loamy Gleyed Matrix (F2)
Iron-Manganese Masses (F12) (LRR D)
Other (Explain in Remarks)
Depleted Matrix (F3)
Redox Dark Surface (F6)
Depleted Dark Surface (F7)
Redox Depressions (F8) unless disturbed or problematic. 3 Indicators of hydrophytic vegetation and
wetland hydrology must be present,
High Water Table (A2) MLRA 1, 2, 4A, and 4B) 4A, and 4B) 2 Location: PL=Pore Lining, M=Matrix.
Restrictive Layer (if observed):
2 cm Muck (A10) (LRR A, E)
Red Parent Material (F21)
Very Shallow Dark Surface (F22)
Histosol (A1)
Histic Epipedon (A2)
Black Histic (A3)
Hydrogen Sulfide (A4)
1 cm Muck (A9) (LRR D, G)
Depleted Below Dark Surface (A11)
Thick Dark Surface (A12)
Sandy Mucky Mineral (S1)
Sandy Gleyed Matrix (S4)
Sandy Redox (S5)
Stripped Matrix (S6)
Loamy Mucky Mineral (F1) (except MLRA 1)
1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains.
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
Field Observations:
(includes capillary fringe)
Shallow depression between backyard that was filled within drainage easement and berm at edge of City's parking lot. No evidence of ponding or inundation for long duration.
No
No
No
Depth (inches):
Depth (inches):
Depth (inches):
Surface Water (A1)
Loamy/Clayey
Matrix
Texture
Depth Redox Features
(inches) Color (moist)
10YR 3/4
10YR 2/1
Color (moist)
0-6
Sparsely Vegetated Concave Surface (B8)
Geomorphic Position (D2)
Surface Soil Cracks (B6) Raised Ant Mounds (D6) (LRR A) Sediment Deposits (B2)
Drift Deposits (B3)
Water Marks (B1)
Algal Mat or Crust (B4)
Wetland Hydrology Indicators:
Salt Crust (B11)
Water-Stained Leaves (B9) (MLRA 1, 2
Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5) Stunted or Stressed Plants (D1) (LRR A)
Inundation Visible on Aerial Imagery (B7)
Iron Deposits (B5)
Saturation (A3)
Secondary Indicators (2 or more required)
Shallow Aquitard (D3)
Drainage Patterns (B10)
Dry-Season Water Table (C2)
Saturation Visible on Aerial Imagery (C9)
Aquatic Invertebrates (B13)
Hydrogen Sulfide Odor (C1)
Oxidized Rhizospheres on Living Roots (C3)
Water-Stained Leaves (B9) (except
Presence of Reduced Iron (C4)
Remarks:
HYDROLOGY
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Coarse gravelly fill from backyard expansion, construction of wet weather equalization basin, or historic.
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) 6-18
SOIL SP-1
coarse gravelly fill with 50% 2.5Y 3/3
Remarks
Loamy/Clayey
ENG FORM 6116-9, JUL 2018 Western Mountains, Valleys, and Coast – Version 2.0 Applicant/Owner: State:
Investigator(s):
Landform (hillside, terrace, etc.): <1
Subregion (LRR): Lat:
Soil Map Unit Name:
X
Are Vegetation , Soil , or Hydrology Are “Normal Circumstances” present? Yes X No Are Vegetation , Soil , or Hydrology
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Yes No X
Yes No X Yes X
Yes No X
)
1. 2. (A)
3. 4. (B)
Sapling/Shrub Stratum (A/B)
1. 2.
3. 4. x 1 =
5. x 2 =
x 3 =
x 4 =
1. x 5 =
2. Column Totals: (A) (B)
3. 4.
5. 6.
7. 8.
9. 10.
11. Woody Vine Stratum
1. 2.
Yes X
U.S. Army Corps of Engineers
WETLAND DETERMINATION DATA SHEET – Western Mountains, Valleys, and Coast Region See ERDC/EL TR-10-3; the proponent agency is CECW-CO-R
OMB Control #: 0710-0024, Exp: 11/30/2024
Requirement Control Symbol EXEMPT:
(Authority: AR 335-15, paragraph 5-2a)
Tree Stratum
Is the Sampled Area
within a Wetland? No
3 2m
30 Remarks:
Indicator
Status
1 2
VEGETATION – Use scientific names of plants.
(Plot size:
Zantedeschia aethiopica
UPL
Herb Stratum
1 No
Oxalis pes-caprae
1 (If no, explain in Remarks.)
Hydric Soil Present?
Wetland Hydrology Present?
2m
naturally problematic? (If needed, explain any answers in Remarks.) (Plot size:
Yes
Number of Dominant Species That
Are OBL, FACW, or FAC:
significantly disturbed?
Slight topographic rise at back of expanded backyard. Criteria not met.
Remarks:
31 FACU species
FAC species
No
OBL species
FACU
3.26 2 - Dominance Test is >50%
Amphilophium buccinatorium
Problematic Hydrophytic Vegetation1
(Explain)
98 5 - Wetland Non-Vascular Plants1
4 - Morphological Adaptations1(Provide supporting
1 UPL
=Total Cover
)
Hydrophytic
Vegetation
Present? No
data in Remarks or on a separate sheet)
(Plot size:
20 Total % Cover of:
=Total Cover
1 - Rapid Test for Hydrophytic Vegetation
120
Multiply by:
40 Prevalence Index = B/A =
0 3 - Prevalence Index is ≤3.01
Hydrophytic Vegetation Indicators:
UPL species
FACW species
Sampling Date:
Sampling Point:
Local relief (concave, convex, none): Slope (%):
4/4/2022
Brendan and Eamon Murphy
Chris Rogers
terrace
City/County: Pacifica / San Mateo
none
Long:
2m
Are climatic / hydrologic conditions on the site typical for this time of year? No S10 T4S R6W
CA SP-2
concave
Section, Township, Range:
50.0%
)
2m )
Prevalence Index worksheet:
0 1
Project/Site: 570 Crespi Drive
LRR A, MLRA 4B
NWI classification:
Dominant
Species?
20 20 FACW
37.597490
Hydrophytic Vegetation Present?
-122.500134 Datum:
Urban Land-Orthents, cut and fill complex 0-5% slopes
(Plot size:
Salix lasiolepis Yes
=Total Cover
OBL
2 No
Non-hydric vegetation dominates sample location. Arroyo willow (Salix lasiolepis; FACW) extend over sample point from plants rooted in area mapped as wetland.
Percent of Dominant Species That
Are OBL, FACW, or FAC:
30 Total Number of Dominant Species
Across All Strata:
Dominance Test worksheet:
% Bare Ground in Herb Stratum
Absolute
% Cover
Yes
15 176
3 54
=Total Cover
Rubus ursinus
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
ENG FORM 6116-9, JUL 2018 Western Mountains, Valleys, and Coast – Version 2.0 Sampling Point:
%% Type1 Loc2
100
98 98 2 C M
Type:
Depth (inches): Hydric Soil Present? Yes No X
Primary Indicators (minimum of one is required; check all that apply) ?
Surface Water Present? Yes X
Water Table Present? Yes X
Saturation Present? Yes X Wetland Hydrology Present? Yes No X SOIL SP-2
Coarse gravelly clay; inclusions (not redox) of 10YR 3/2 Sandy clay loam
Prominent redox concentrations
Remarks
Loamy/Clayey
Drainage Patterns (B10)
Dry-Season Water Table (C2)
Saturation Visible on Aerial Imagery (C9)
Aquatic Invertebrates (B13)
Hydrogen Sulfide Odor (C1)
Oxidized Rhizospheres on Living Roots (C3)
Water-Stained Leaves (B9) (except
Presence of Reduced Iron (C4)
Remarks:
HYDROLOGY
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Coarse gravelly fill from backyard expansion.
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) 9-15
Sparsely Vegetated Concave Surface (B8)
Geomorphic Position (D2)
Surface Soil Cracks (B6) Raised Ant Mounds (D6) (LRR A) Sediment Deposits (B2)
Drift Deposits (B3)
Water Marks (B1)
Algal Mat or Crust (B4)
Wetland Hydrology Indicators:
Salt Crust (B11)
Water-Stained Leaves (B9) (MLRA 1, 2
Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5) Stunted or Stressed Plants (D1) (LRR A)
Inundation Visible on Aerial Imagery (B7)
Iron Deposits (B5)
Saturation (A3)
Secondary Indicators (2 or more required)
Shallow Aquitard (D3)
(inches) Color (moist)
2.5Y 3/2
10YR 5/6
Color (moist)
7.5YR 5/8
0-9
Surface Water (A1)
Loamy/Clayey
2.5Y 3/2
Matrix
Texture
15-18 Sandy
Depth Redox Features
Remarks:
Field Observations:
(includes capillary fringe)
Slight topographic rise against back backyard fence. No hydrology indicators. The sample point likely experiences periods of inundation or saturation following significant storm events, but it is not a persistent condition.
No
No
No
Depth (inches):
Depth (inches):
Depth (inches):
High Water Table (A2) MLRA 1, 2, 4A, and 4B) 4A, and 4B) 2 Location: PL=Pore Lining, M=Matrix.
Restrictive Layer (if observed):
2 cm Muck (A10) (LRR A, E)
Red Parent Material (F21)
Very Shallow Dark Surface (F22)
Histosol (A1)
Histic Epipedon (A2)
Black Histic (A3)
Hydrogen Sulfide (A4)
1 cm Muck (A9) (LRR D, G)
Depleted Below Dark Surface (A11)
Thick Dark Surface (A12)
Sandy Mucky Mineral (S1)
Sandy Gleyed Matrix (S4)
Sandy Redox (S5)
Stripped Matrix (S6)
Loamy Mucky Mineral (F1) (except MLRA 1)
1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains.
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
2.5 cm Mucky Peat or Peat (S2) (LRR G)
Loamy Gleyed Matrix (F2)
Iron-Manganese Masses (F12) (LRR D)
Other (Explain in Remarks)
Depleted Matrix (F3)
Redox Dark Surface (F6)
Depleted Dark Surface (F7)
Redox Depressions (F8) unless disturbed or problematic. 3 Indicators of hydrophytic vegetation and
wetland hydrology must be present,
ENG FORM 6116-9, JUL 2018 Western Mountains, Valleys, and Coast – Version 2.0 Applicant/Owner: State:
Investigator(s):
Landform (hillside, terrace, etc.): <1
Subregion (LRR): Lat:
Soil Map Unit Name:
X
Are Vegetation , Soil , or Hydrology Are “Normal Circumstances” present? Yes X No Are Vegetation , Soil , or Hydrology
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Yes x No
Yes X No Yes X
Yes X No
)
1. 2. (A)
3. 4. (B)
Sapling/Shrub Stratum (A/B)
1. 2.
3. 4. x 1 =
5. x 2 =
x 3 =
x 4 =
1. x 5 =
2. Column Totals: (A) (B)
3. 4.
5. 6.
7. 8. X
9. 10.
11. Woody Vine Stratum
1. 2.
Yes x
Non-hydric vegetation dominates sample location. Willow canopy extends over sample location from plants rooted in area mapped as wetland.
Percent of Dominant Species That
Are OBL, FACW, or FAC:
15 Total Number of Dominant Species
Across All Strata:
Dominance Test worksheet:
% Bare Ground in Herb Stratum
Absolute
% Cover
Yes
0 180
0 75
=Total Cover
Rubus ursinus
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
(Plot size:
Salix lasiolepis Yes
=Total Cover
Project/Site: 570 Crespi Drive
LRR A, MLRA 4B
NWI classification:
Dominant
Species?
60 60 FACW
37.597518
Hydrophytic Vegetation Present?
-122.500056 Datum:
Urban Land-Orthents, cut and fill complex 0-5% slopes none Long:
2m
Are climatic / hydrologic conditions on the site typical for this time of year? No S10 T4S R6W
CA SP-3
concave
Section, Township, Range:
50.0%
)
2m )
Prevalence Index worksheet:
0 0
Sampling Date:
Sampling Point:
Local relief (concave, convex, none): Slope (%):
4/4/2022
Brendan and Eamon Murphy
Chris Rogers
terrace
City/County: Pacifica / San Mateo
60 Total % Cover of:
=Total Cover
1 - Rapid Test for Hydrophytic Vegetation
60 Multiply by:
120
Prevalence Index = B/A =
0 3 - Prevalence Index is ≤3.01
Hydrophytic Vegetation Indicators:
UPL species
FACW species
Problematic Hydrophytic Vegetation1
(Explain)
65 5 - Wetland Non-Vascular Plants1
4 - Morphological Adaptations1(Provide supporting
=Total Cover
)
Hydrophytic
Vegetation
Present? No
data in Remarks or on a separate sheet)
(Plot size:
Remarks:
15 FACU species
FAC species
OBL species
FACU
2.40 2 - Dominance Test is >50%
(If no, explain in Remarks.)
Hydric Soil Present?
Wetland Hydrology Present?
2m
naturally problematic? (If needed, explain any answers in Remarks.) (Plot size:
Yes
Number of Dominant Species That
Are OBL, FACW, or FAC:
significantly disturbed?
All three criteria are met.
Indicator
Status
1 2
VEGETATION – Use scientific names of plants.
Herb Stratum (Plot size:
0 U.S. Army Corps of Engineers
WETLAND DETERMINATION DATA SHEET – Western Mountains, Valleys, and Coast Region See ERDC/EL TR-10-3; the proponent agency is CECW-CO-R
OMB Control #: 0710-0024, Exp: 11/30/2024
Requirement Control Symbol EXEMPT:
(Authority: AR 335-15, paragraph 5-2a)
Tree Stratum
Is the Sampled Area
within a Wetland? No
2m
15 Remarks:
ENG FORM 6116-9, JUL 2018 Western Mountains, Valleys, and Coast – Version 2.0 Sampling Point:
%% Type1 Loc2
100
48 2 C M
X
Type:
Depth (inches): Hydric Soil Present? Yes X No
Primary Indicators (minimum of one is required; check all that apply) X
X
X
X
?
Surface Water Present? Yes X
Water Table Present? Yes X
Saturation Present? Yes X Wetland Hydrology Present? Yes X No
2.5 cm Mucky Peat or Peat (S2) (LRR G)
Loamy Gleyed Matrix (F2)
Iron-Manganese Masses (F12) (LRR D)
Other (Explain in Remarks)
Depleted Matrix (F3)
Redox Dark Surface (F6)
Depleted Dark Surface (F7)
Redox Depressions (F8) unless disturbed or problematic. 3 Indicators of hydrophytic vegetation and
wetland hydrology must be present,
High Water Table (A2) MLRA 1, 2, 4A, and 4B) 4A, and 4B) 2 Location: PL=Pore Lining, M=Matrix.
Restrictive Layer (if observed):
2 cm Muck (A10) (LRR A, E)
Red Parent Material (F21)
Very Shallow Dark Surface (F22)
Histosol (A1)
Histic Epipedon (A2)
Black Histic (A3)
Hydrogen Sulfide (A4)
1 cm Muck (A9) (LRR D, G)
Depleted Below Dark Surface (A11)
Thick Dark Surface (A12)
Sandy Mucky Mineral (S1)
Sandy Gleyed Matrix (S4)
Sandy Redox (S5)
Stripped Matrix (S6)
Loamy Mucky Mineral (F1) (except MLRA 1)
1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains.
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
Field Observations:
(includes capillary fringe)
Ground slope to north where standing water is accumulated. Seaonal high water table and evidence of long duration saturation and/or inundation.
No
No
No
Depth (inches):
Depth (inches):
Depth (inches):
Surface Water (A1)
Loamy/Clayey
Matrix
Texture
15-20
Depth Redox Features
(inches) Color (moist)
2.5Y 3/2
10YR 2/1
Color (moist)
2.5YR 3/6
0-6
Sparsely Vegetated Concave Surface (B8)
Geomorphic Position (D2)
Surface Soil Cracks (B6) Raised Ant Mounds (D6) (LRR A) Sediment Deposits (B2)
Drift Deposits (B3)
Water Marks (B1)
Algal Mat or Crust (B4)
Wetland Hydrology Indicators:
Salt Crust (B11)
Water-Stained Leaves (B9) (MLRA 1, 2
Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5) Stunted or Stressed Plants (D1) (LRR A)
Inundation Visible on Aerial Imagery (B7)
Iron Deposits (B5)
Saturation (A3)
Secondary Indicators (2 or more required)
Shallow Aquitard (D3)
Drainage Patterns (B10)
Dry-Season Water Table (C2)
Saturation Visible on Aerial Imagery (C9)
Aquatic Invertebrates (B13)
Hydrogen Sulfide Odor (C1)
Oxidized Rhizospheres on Living Roots (C3)
Water-Stained Leaves (B9) (except
Presence of Reduced Iron (C4)
Remarks:
HYDROLOGY
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Native soil, not fill (urban land/orthents) as mapped. Evidence of hydric soil resulting from long duration saturation and/or inundation.
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) 6-15
SOIL SP-3
Silty clay, organic; roots and worms.
Gravelly clay; 45% 2.5Y 4/2, 5% 10YR 2/1
groundwater
Remarks
Loamy/Clayey
ENG FORM 6116-9, JUL 2018 Western Mountains, Valleys, and Coast – Version 2.0 April 8, 2022
Christian Murdock, ACICP
Deputy Director of Planning
City of Pacifica, Planning Department
540 Crespi Drive
Pacifica, CA 94044
Re: 570 Crespi Drive Development Proposal
Clarification of Wetland Boundary in Southern Part of Project Site Dear Christian:
This letter clarifies the extent of wetlands near the southern boundary of the two parcels that comprise the project site, and in relation to the location of a proposed emergency overflow riser (i.e., drain inlet), and the City’s drainage easement located along the southern boundary. The location of the inlet was shown on Tentative Map Sheet TM-3 (dated 1/21/21) which was included in the project submittal to the City and evaluated as part of the Mitigated Negative Declaration.
However, that location is within an area that meets the criteria for jurisdictional wetlands. Installation of the riser within the wetlands could trigger the need for regulatory permits from federal and state regulatory agencies.
My original wetland delineation map and report, completed prior to the project submittal, focused on the location and extent of jurisdictional wetlands toward the northern portion of the project site, where the objective was to avoid impacts to wetlands resulting from the proposed residential development project. The wetland delineation followed the rigorous federal protocol for establishing a jurisdictional wetland boundary, including documentation of vegetation, soil and hydrological conditions based on multiple sample points. The results of the delineation guided the applicant to develop a design footprint that did not encroach on the northern wetland boundary. In the southern portion of the project, which is dominated by dense and often impenetrable willow scrub, the extent of wetlands was extrapolated based on the presence of willow wetlands elsewhere on the site, and on the neighboring City’s Community Center and WetWeather Equalization Basin parcel. The project study area boundary also was less precise with respect to the actual parcel boundary, again because the priority for impact avoidance was focused on the wetland boundary closest to the proposed buildings.
An alternative location for the riser is now proposed by the applicant close to the southwest corner of the project site, as shown on the attached Sheet A1.14. Upon inspection, I agree that this is an appropriate location for the emergency riser because it would avoid impacts to jurisdictional wetlands.
On March 31 and April 4, 2022, I evaluated vegetation, soil and hydrological conditions in the southwest corner of the project site (the City’s parcel) to more precisely determine the boundary between jurisdictional and non-jurisdiction areas. Consistent with the U.S. Army Corp of Engineers
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2 wetland delineation methodology, I documented conditions at three sample locations, SP-1, SP-2 and SP-3, also shown on Sheet A1.14, which also shows the location of the jurisdictional boundary, and the wooden backyard fence for several homes on Anza Avenue. The technical results of these samples are summarized below.
The proposed location of the emergency riser is located in portion of the City’s drainage easement that was established for the purpose of conveying surface and subsurface stormwater toward the pump station near the beach. The riser would be consistent with that objective, would provide a benefit to the proposed project as well as to the adjacent residential properties, and would not interfere with other established uses of the easement. The new proposed location of the riser also would not result in any temporary or permanent impacts to wetland habitat.
Sample Point SP-1 is at the location of the proposed emergency riser within the City’s existing drainage easement, next to the wooden backyard fence and close to the existing underground storm drain. The location is in a small depression that will facilitate drainage. The dominant vegetation is Ngaio tree (Myoporum laetum; UPL1 ), an invasive non-native species that is not a wetland indicator. California blackberry (Rubus ursinus; FACU) and Bermuda buttercup (Oxalis pescaprae; no indicator, presumed UPL) also are located in the immediate vicinity of the sample point. These species do not meet the criterion for wetland vegetation. Branches from nearby arroyo willow (Salix lasiolepis; OBL) extend over this site from plants that are rooted nearby, as mapped in the original wetland delineation.
The soil in this location is a clay loam consisting of a dark surface horizon (0-6 inches; 10YR2/1) lacking redoximorphic features. The lower horizon consists of pale yellow coarse gravelly clay (6- 18+ inches; 10YR3/4 and 2.5Y3/3), with angular gravel that suggests its origin is either fill or overburden placed when the neighboring yards were extended into the easement. The soil does not exhibit indicators of prolonged inundation or saturation, and is presumed not to be hydric (i.e., not a wetland soil).
To the east of SP-1, a slight rise of 1 to 2 feet separates the proposed riser location from the area where wetland hydrology is apparent as prolonged inundation and soil saturation supporting the willow-dominated portion of the project site. The sample point likely experiences periods of inundation or saturation following significant storm events, but it is not a persistent condition.
None of the three criteria (vegetation, soil or hydrology) are met, therefore, Sample Point SP-1 is non-jurisdictional.
Sample Point SP-2 is located on the slight topographic rise described above. The vegetation cover is dominated by arroyo willow extending to the fence line but not rooted at the sample point, California blackberry, Mexican blood trumpet vine (Amphilophium buccinatorium, a garden escape; no indicator, presumed UPL). Bermuda buttercup and calla lily (Zantedeschia aethiopica; OBL) are 1 Plant species are classified according to their probability of occurring in jurisdictional wetlands: Obligate wetland (OBL) – almost always occurs in wetlands (>99% probability); Facultative wetland (FACW) – usually occurs in wetlands (67-99%), but occasionally in non-wetlands (1-33%); Facultative (FAC) – equally likely to occur in wetlands and non-wetlands (33-67%); Facultative upland (FACU) – usually occurs in nonwetlands (67-99%), but occasionally occurs in wetlands (1-33%); Obligate upland (UPL) – almost always occurs in non-wetlands (>99%).
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3 present at 1-2% cover each. In the absence of dominant wetland indicator species, the vegetation criterion is not met.
The ground surface is relative bare, with yard waste debris. Soil at SP-2 is also likely fill material, with a pale yellow gravelly clay surface horizon (0-9 inches; 10YR5/6) with inclusions of darker organic-enriched material (10YR3/2). Below this is a transitional stratum of coarse gravelly clay (9- 15 inches; 2.5YR3/2). Below 15 inches, the soil transitions to sandy clay, possibly the cut and fill orthents that are mapped in the Soil Survey report. The color is pale yellow (2.5Y3/2) with up to 2% redox concentrations (7.5YR5/8) indicating periodic endosaturation from seasonal high groundwater. Although the deeper horizon indicates influence from nearby areas of prolonged saturation, the overall profile at this sample point does not conform to the hydric soil criteria.
The location adjacent to the wooden backyard fence line is slightly higher in elevation than the area of prolonged inundation and soil saturation supporting the willow-dominated portion of the project site to the north. The sample point likely experiences periods of inundation or saturation following significant storm events, but it is not a persistent condition.
None of the three criteria (vegetation, soil or hydrology) are met, therefore, Sample Point SP-2 is non-jurisdictional.
Sample Point SP-3 is located in the middle of the arroyo willow thicket, approximately 20 feet north of the wood fence. Vegetation, soil and hydrology conditions differ markedly from SP-1 and SP-2. Willow trees and shrubs at this location support a dense canopy, and meet the hydrophytic vegetation criterion. California blackberry also is present, but no other plants species are in the understory; the ground covered with accumulated branches and decomposing plant debris.
The soil is native (not fill), and exhibits hydric characteristics: from 0-6 inches, it is black organic enriched silty clay (10YR2/1); from 6-15+ inches, it is saturated gravelly clay (2.5Y3/2 and
2.5Y4/2), with 5% dark inclusions (10YR/2/1) of illuviated clay and/organic matter, and distinct redox concentrations of 2.5Y3/6. This soil meets the hydric soil definition of “Redox Dark Surface”2 at sample point SP-3.
Groundwater was at 15 inches. The ground slopes slightly to the north, where standing water was accumulated at the surface, providing a clear indication of the seasonally high water table that supports the willow-dominated wetland in the majority of the southern part of the project site.
The hydrology criterion is met at sample point SP-3.
All three wetland criteria are met at SP-3, therefore the site is jurisdictional. 2 U.S. Department of Agric., Nat. Res. Consv. Serv. 2010. Field Indicators of Hydric Soils.in the United States.
Version 7.0. L.M. Vasilas, G.W. Hurt, and C.V. Noble (eds). USDA, NRCS, in cooperation with the National technical Committee for Hydric Soils.
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4 If you have any questions regarding this matter, please call me at (415) 254-4835.
Sincerely,
Chris Rogers
cc: Brendan Murphy, Eamon Murphy, Stuart Welte