Wetland Delineation of Neslon Reservoir

PRELIMINARY JURISDICTIONAL DETERMINATION FOR

NELSON RESERVOIR CAL POLY CAMPUS, SAN LUIS OBISPO, CALIFORNIA

PREPARED FOR: ROBERT SLOAN

NATURAL RESOURCES MANAGEMENT & ENVIRONMENTAL SCIENCES DEPARTMENT CALIFORNIA POLYTECHNIC STATE UNIVERSITY

PREPARED BY: MACKENZIE TAGGART

[email protected] WETLANDS-‐ SS 421

SPRING QUARTER 2014

NELSON RESERVOIR PRELIMINARY JURISDICTIONAL DETERMINATION

1. INTRODUCTION

1.1. PURPOSE OF REPORT

This Preliminary Jurisdictional Determination serves as a summary of the current soil, vegetative, and hydrologic conditions of Nelson Reservoir associated with the construction of a dock along the northern bank. This report will explain the methodology behind the delineation of this site and will identify, and outline, the jurisdictional boundaries held by the various agencies involved with the project.

1.2. SITE LOCATION AND EXISTING CONDITIONS

Nelson Reservoir is located in the upper northwest portion of the Cal Poly campus between Highway 1 and Stenner Creek Road (refer to Figure 1). The reservoir is currently used for overflow from Middlecamp Reservoir, located further North from Nelson on the Cal Poly Campus, and as a water distribution site to other portions of the campus. The reservoir is located at the base of a small watershed, and though primarily fed by Middlecamp Reservoir, runoff and drainage from the watershed also contribute to water levels of the reservoir. Adjacent to Stenner Creek, the reservoir shares a connection to the creek through the flow of groundwater. The vegetation at the site consists various trees and herbaceous species including Eucalyptus, Iris, and Bullrush. The dominant soils in the area are part of the Los Osos Loam 15-‐30 percent slope series with loam and clay loam textures. Nelson Reservoir went through extensive alterations many years ago, remnants of this can be seen as sandy fill material in soil horizons, however due to the length of time that has passed since, circumstances are considered normal.

2. REGULATORY BACKGROUND

2.1. US ARMY CORPS OF ENGINEERS The U.S. Army Corps of Engineers has jurisdiction over two categories of water: navigable waters of the United States, and waters of the United States. Navigable waters of the United States are regulated under Section 10 of the Rivers and Harbors Act. The Army Corps regulates any construction, dredging, of excavation in these waters. Under Section 404 of the Clean Water Act, the Army Corps regulates permits for the discharges of dredged of fill material in to waters of the United States. These waters include navigable waters, lakes, ponds, small streams, ditches, and adjacent wetlands. Isolated waters may also be waters of the United States. (U.S. Army Corps of Engineers, 2014)

2.2. REGIONAL WATER QUALITY CONTROL BOARD

The Central Coast Water Board is the State regulatory agency responsible for protecting the quality of groundwater and surface waters within its region. The Porter-‐Cologne Act establishes a program for the protection of water quality and beneficial uses of water. It applies to surface waters (including wetlands), groundwater, and point and non-‐point sources of pollution. Under section 401 of the Clean Water Act and the Porter-‐Cologne Act, the Regional Boards regulate the discharge of fill


or dredged material, especially in the case of wetlands, as they are prone to illegal filling and dredging. (Central Coast RWQCB, 2014)

2.3. CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE

The California Department of Fish and Wildlife has jurisdiction over the conservation, protection, and management of fish, wildlife, native plants, and habitat necessary for biologically sustainable populations of those species. Under Division 2, Chapter 6 of the California Fish and Game Code, the CDFW regulates all diversions, obstructions, or changes to the natural flow or bed, channel, or bank of any river, stream, or natural/ man made lake, which supports fish or wildlife. The CA Fish and Wildlife service also assists in the regulation of fill and dredge permits under section 404 of the CWA. (CDFW, 2014)

3. METHODOLOGY

Before beginning the field delineation, the full circumference of reservoir was inspected to determine an appropriate spot for the examination of hydrologic, soil, and vegetative features. An area along the northern segment of the reservoir was chosen (refer to Figure 2). Two soil pits were dug for sampling within the area of interest. The soil pits were dug with a distance of 6 feet between them and with dimensions of 12 inches wide and 16 inches deep. Soils were examined at each sampling point to determine texture, color, depth of horizons, and if hydric soil indicators were present.

A circular plot with a diameter of 20 feet was examined around each sampling point to distinguish vegetation strata and species present. Percent cover was estimated for each identifiable species across represented strata. The plot area was also examined to identify any primary or secondary wetland hydrology indicators that may be present. Topographic maps of the area were consulted to determine the connectivity of the reservoir to other waters for the purpose of determining jurisdictional areas. The delineation of Nelson Reservoir was conducted per the USACE Wetland Delineation Manual: Arid West Region (Version 2.0). USACE wetland determination data forms were used to catalog the vegetative, soil, and hydrologic information of Nelson Reservoir; a sheet was filled out for each of the sampling points. The USACE Arid West 2014 Regional Wetland Plant List was consulted when identifying vegetation in the area. Munsell Soil Charts and USDA Field Indicators of Hydric Soils were used utilized when coloring soils at each sampling point. A USGS topographic map of Nelson Reservoir and surrounding areas was used to identify receiving waters and connection of the reservoir to other bodies of water. Results are discussed below.

4. RESULTS

4.1. SOIL CONDITIONS Two pits were dug for the examination of the soil surrounding Nelson Reservoir (refer to Figure 2). Both sampling points are part of the Los Osos Loam 15-‐30 percent slope soil series. Sampling point 1 was dug 9 feet from the edge of the reservoir, determined based on where surface water was present (refer to Appendix B, Photo 5). The soils at this site were textured as loam and clay loam, with clay percentage increasing further down the pit. Three horizons were identified at this location;


the upper horizon was 2.5 inches thick and dark in color with a high percentage of organic matter in the form of eucalyptus leaves. The second horizon consisted of sandy fill material from a renovation of the reservoir many years ago and showed little morphological evidence. The last horizon was moist throughout with around 10 percent concentrations from the oxidation of iron in the soil. No hydric soil indicators were present. Sampling point 2 was dug 3 feet from the edge of the reservoir; 3 horizons were also identified (refer to Appendix B, Photos 1-‐3). The upper horizon was 2 inches deep and very dark in color with a loam texture and high percentage of organic matter. The second horizon crossed into the water table and was saturated 4 inches form the surface; a strong hydrogen sulfide odor was present. The lower horizon had a gleyed matrix with around 5 percent concentrations of oxidized iron in the form of soft masses. This sampling point met the hydric soil indicators or A12 Thick Dark Surface, F2 Loamy Gleyed Matrix, and F8 Redox Depressions.

4.2. VEGETATIVE CONDITIONS

The vegetation at both sampling points consisted of trees and herbaceous species (refer to Appendix B, Photo 9). A type of Eucalyptus, known as Eucalyptus camaldulensis, a species of reed grass, and Bullrush, were dominant at both sampling points. Other non-‐ dominant species prevalent at both sites included the Pale Yellow Iris (Iris pseudacorus), Spikerush, and Tall Flatsedge (refer to Appendix B, Photo 6). The dominance test and prevalence index were met at both sampling points, indicating the presence of hydrophytic vegetation.

4.3. HYDROLOGIC CONDITIONS

Nelson Reservoir has two main sources of water: the primary source is overflow from Middlecamp reservoir, and the second source is downslope drainage from the small watershed located above the reservoir (refer to Figure1). The reservoir is also connected to the adjacent Stenner Creek through the flow of groundwater from the reservoir to the creek. The hydrologic conditions at Nelson Reservoir are not considered to be normal due to the prolonged drought San Luis Obispo County is in. Though the soils at sampling point 1 were moist throughout, this area did not meet any wetland hydrology indicators. Sampling point 2 however, met three wetland hydrology indicators: High Water Table A2, Saturation A3, and Hydrogen Sulfide Odor C1. While digging at sampling point 2, water was seeping into the pit relatively fast. The water table was present at a depth of 7 inches below the surface and Saturation was present at a depth of 4 inches.

4.4. DISCUSSION

Based on the soil, vegetative, and hydrologic conditions present at sampling point 1, this area does not meet the requirements of a wetland per USACE regulations. Sampling point 1 met the hydrophytic vegetation requirements of a wetland by passing the dominance test; however, no hydric soil or wetland hydrology indicators were identified. At sampling point 2, all three wetland indicators were met, classifying the area as a wetland per USACE regulations. The delineation line around the wetland is approximately 6 feet from the edge of the reservoir, passing between sampling points 1 and 2.


5. PRELIMINARY JURISDICTIONAL DETERMINATION

The objective of this preliminary jurisdictional determination is to identify the federal and state jurisdictional areas within the project site. The following summarizes the jurisdictional areas according to each regulatory agency. 5.1. U.S. ARMY CORPS OF ENGINEERS

The investigation of the two sampling points along Nelson Reservoir identified a portion within approximately 5 feet from the edge of the reservoir to be a Wetland subject to USACE jurisdiction under Section 404 of the Clean Water Act (refer to Figure 2). Sampling point 2 is included in this wetland, which is classified as Lacustrine. Under USACE regulations, a jurisdictional wetland must have all three wetland indicators of hydrology, hydric soils, and hydric vegetation for some duration during the growing season. This identified are meets all three requirements to be regulated by the Army Corps and will likely be considered jurisdictional. USACE also regulates all navigable waters of the United States, wetland and non-‐wetland, where navigable is defined as a significant nexus of connections from the feature to a navigable body of water. Nelson Reservoir has a connection to Stenner Creek, which then flows to the Pacific Ocean, which is considered a navigable body of water. It is likely the Army Corps will consider this wetland jurisdictional based on its nexus to navigable waters.

5.2. CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE

The CDFW is responsible for regulating projects that have a potential to impact state jurisdictional wetlands. CDFW considers any area the meets the requirements of one of the USACE wetlands indicators as a state wetland. Based on CDFW regulations, the wetland boundary now includes both sampling points 1 and 2 and extends out to about 12-‐15 feet from the edge of the reservoir (refer to Figure 2). Though sampling point 1 only meets the hydrophytic vegetation requirement for a wetland, under CDFW regulation it is considered a wetland of the state and jurisdictional. 5.3. REGIONAL WATER QUALITY CONTROL BOARD

The RWQCB defines a wetland as an area if, under normal circumstances, has continuous or recurrent saturation of the upper substrate caused by groundwater, or shallow surface water, or both; the duration of such saturation is sufficient to cause anaerobic conditions in the upper substrate; and the area either lacks vegetation or the vegetation is dominated by hydrophytes. (RWQCB, 2014). Based on the regulations for jurisdiction, sampling point 2 meets the requirements of a wetland and would be considered jurisdictional; however, sampling point 1 only meets one of the requirements, and thus would not be considered jurisdictional. The RWQCB will be the share the same wetland delineation boundary as USACE (refer to Figure 2).


6. REFERENCES "California Department of Fish and Wildlife." California Department of Fish and Wildlife. State of California, n.d. Web. 04 June 2014. <https://www.wildlife.ca.gov/>. "State Water Resources Control Board." State Water Resources Control Board. State of California, n.d. Web. 04 June 2014. <http://www.waterboards.ca.gov/>. "Jurisdictional Information." Headquarters U.S. Army Corps of Engineers Missions Civil Works Regulatory Program and Permits Juris_info. U.S. Army Corps of Engineers, n.d. Web. 04 June 2014. <http://www.usace.army.mil/Missions/CivilWorks/RegulatoryProgramandPermits/juris_info.aspx>. Mitsch, William J., and James G. Gosselink. Wetlands. New Jersey: John Wiley & Sons, 2007. Print. Engineers, U.S. Army Corps Of. "Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0)." (2008): n. pag. US Army Corps of Engineers, 2008. Web. 3 June 2014. <http://www.usace.army.mil/Portals/2/docs/civilworks/regulatory/reg_supp/trel08-‐28.pdf>.


FIGURES

Figure 1: USGS topographic map of project location

Figure 2: Aerial image of jurisdictional areas

Sampling Point 1

Sampling Point 2

USACE & RWQCB Boundary

CDFW Boundary


APPENDIX Appendix A: Data Sheets for Sampling points 1 and 2


Appendix B: Photo Documentation Photo 1: Sampling point 2

Photo 3: Sampling point

Photo 2: Sampling point 2



Photo 5: Edge of reservoir & native vegetation


Photo 9: Vegetation along the Northern bank

Photo 6: Iris species growing along reservoir


Documents

Wetland Delineation of Neslon Reservoir