4.3 Hydrology and Water Quality

4.3 Hydrology and Water Quality

4.3 HYDROLOGY AND WATER QUALITY

Introduction

This section of the EIR identifies regional and local surface water and groundwater resources that could affect or be affected by development of the proposed project. Specifically, this section addresses potential hydrologic effects related to stormwater runoff, flooding, water quality, and groundwater recharge. Site characteristics such as regional and local drainage and flooding conditions and water quality are described based on site-specific information developed for the proposed project and published technical information, as indicated in footnoted references. The primary source of information regarding drainage and flooding conditions is a technical report prepared by Civil Engineering Solutions Inc. (CES) (Meadowlands Preliminary Drainage Report (Drainage Report), dated March 29, 2007), which is available for review at the City of Lincoln, Community Development Department. Primary background information comes from a variety of publicly available documents, including the City of Lincoln General Plan Draft EIR (State Clearinghouse No. 2005112003, October 2006).

The Initial Study (IS) for the proposed project (see Appendix C) concluded there would be no impacts related to flooding as a result of a failure of a dam or levee, or impacts resulting from seiche, tsunami, or mudflow. Therefore, these issues are not further addressed in this EIR. Topics identified as potentially significant in the IS are addressed in this section.

Comment letters received in response to the Notice of Preparation (NOP) (see Appendix A and B), included a comment letter from the Placer County Flood Control and Water Conservation District that requested analysis of impacts related to increases in peak flow rates and volumes at downstream locations, exceeding the capacity of existing stormwater facilities and floodways, and alterations to the 100-year floodplain. These issues are addressed in this EIR.

The potential environmental effects related to proposed water supplies are addressed in Section 4.6, Utilities.

Environmental Setting

Regional Hydrology and Water Quality

The project site is located in the northeastern portion of the City of Lincoln, in Placer County. Placer County is located in the Central Valley, northeast of Sacramento, along the base of and into the Sierra Nevada foothills. Markham Ravine, Auburn Ravine, Ingram Slough, and Orchard Creek are westerly-flowing major streams that pass through the City of Lincoln. The project site is located within the Markham Ravine watershed, as shown in Figure 4.3-1.

The Markham Ravine watershed is a largely rural area in Placer County, totaling approximately 32square miles within the 235-square-mile Cross Canal watershed. Markham Ravine originates east of Lincoln in the foothills and flows west to the East Side Canal approximately seven miles southwest, just north of where Auburn Ravine flows into the East Side Canal. The East Side Canal drains to the Cross Canal approximately one mile east of SR 65. The Cross Canal passes through an extensive levee network before discharging into the Sacramento River just south of its confluence with the Feather River, approximately 11 miles west of the City of Lincoln. Markham Ravine has well-defined channels that historically conveyed seasonal flows before development of mining canals, conveyance of water irrigated agriculture, and construction of hydropower generation facilities.

Markham Ravine drains the central areas of the City of Lincoln, and areas north of existing developed areas. Through the City of Lincoln, Markham Ravine consists of three channels. The main channel is the Central Branch of Markham Ravine, passing through the city from the east to the west/southwest. Approximately three square miles of rural and partially developed land are tributary to the main branch east of SR 65. The southern channel collects runoff from the central and western areas of the city, west of SR 65. This tributary to Markham Ravine has been placed into a pipe system throughout most of the developed area of the city. The pipe daylights to a channel system near the intersection of O and 8th Streets in downtown Lincoln. From this location flows are conveyed west to Joiner Parkway, where flows return to a natural swale flowing generally west and then northwest, joining the main branch of Markham Ravine near Nicolaus Road.

The northern channel of Markham Ravine, also known as Clay Creek, enters the City of Lincoln, crossing SR 65, at the Foskett Ranch subdivision. At the project boundary, the creek has been channelized along the north side of Venture Parkway, to the intersection of Lakeside Drive. West of this intersection, flows are conveyed through pipes for approximately 1,700 feet to a detention basin located along the northern boundary of the Teal Hollow subdivision. Beyond the culvert restriction at the west end of the detention basin, flows are returned to a natural channel for approximately 1,800 feet to the junction with the main branch of Markham Ravine.

CES is currently conducting hydrologic and hydraulic analyses on the Markham Ravine watershed to update previous information on topography and runoff into the ravine. This information will be used to complete the North Lincoln Master Drainage Plan (NLMDP) currently being prepared by the City. The updated model prepared for the NLMDP will be a more accurate reference base model for the determination of project impacts in the watershed, based on a better correlation with the existing watershed conditions.

Flooding

Flooding within Markham Ravine is known to occur mostly in the rural areas of the City, where culvert and bridge crossings do not provide adequate capacity. East of SR 65, flooding occurs at Gladding Road and McCourtney Roads annually. West of SR 65, flooding has occurred at the low areas of Nicolaus Road (not at the bridge location). At Nelson Lane flooding is expected annually. The SR 65 Bridge is expected to overtop in storm events greater than the 10-year, and the Union Pacific Railroad Bridge is only expected to be overtopped in a 50-year or greater event. These estimates were supported by the December 31, 2005 flood event.

Other private crossings of the Ravine are expected to overtop annually. At the North Tributary, Clay Creek, shallow flooding in the remaining natural areas of the creek is still expected. The developed areas of the Creek are protected from flooding in the 100-year event.

At the southern tributary, 100-year protection is provided from Joiner Park, downstream to the City Limits. Shallow flooding beyond the stream banks is expected in flood events, in the natural stream areas downstream of Joiner Parkway. Upstream of Joiner Park, the existing channel and storm drain systems may not provide 100-year protection to the existing residential areas in the Fifth through Eighth Street Corridor between H Street and Q streets.

Stormwater Volume and Retention Facilities[1]

Development within the City and updated methodology and assumptions to calculate runoff volumes have resulted in the construction of the City’s Stormwater Retention Facility (SWRF) to mitigate flow and volumes from new development in the Orchard Creek watershed. This facility was developed as a result of a Settlement Agreement established between Sutter County and the City of Lincoln and Placer County in 1998.[2] Upon completion, the SWRF had a capacity of 720 acre-feet, 86 acre-feet more capacity than required to mitigate the current runoff volumes (634 acre-feet).[3] The remaining 86 acre-feet (ac-ft) of basin volume is used to provide the required four feet of freeboard in the basin and to ensure no net loss of area for irrigation fields at the Lincoln Wastewater Treatment Reclamation Facility (WWTRF).[4] Although the SWRF was completed, an additional retention facility was approved in the Coon Creek watershed, north of the Markham Ravine watershed to expand storage space in the City (“Lakeview Farms Volumetric Mitigation Facility”). After constructing the new retention basin, the City would potentially remove the peak flow diversion at the existing SWRF basin off of Ingram Slough and use the existing SWRF basin at the WWTRF for future wastewater storage. A Mitigated Negative Declaration (MND) for the new retention facility in the Coon Creek watershed was prepared in June 2006 and was certified by the Lincoln City Council in December 2006.[5] The Coon Creek facility would hold approximately 1,030 ac-ft of stormwater and would be used to mitigate the volumetric impacts from current developments’ stormwater runoff volumes currently served by the SWRF with an additional 788 ac-ft available for future development runoff volumes.[6]

Water Quality

Water quality objectives for the Sacramento River and its tributaries, including Markham Ravine, are specified in The Water Quality Control Plan for the Sacramento River Basin and San Joaquin River Basin (Basin Plan) prepared by the Central Valley Regional Water Quality Control Board (CVRWQCB) in compliance with the federal Clean Water Act (CWA) and the state Porter-Cologne Water Quality Control Act (see “Regulatory Setting,” below).[7] The Basin Plan establishes water quality objectives, and implementation programs to meet stated objectives and to protect the beneficial uses of water in the Sacramento-San Joaquin River Basin.

Beneficial uses for the Sacramento River include municipal and domestic supply, agricultural supply, recreation, and aquatic and wildlife habitat. These beneficial uses also apply to Markham Ravine because it ultimately discharges to the Sacramento River. Because the City of Lincoln is located within the CVRWQCB’s jurisdiction, all discharges to surface water or groundwater are subject to the Basin Plan requirements.

Surface water quality in the project area can generally be characterized by surrounding land uses. The historical land use along Markham Ravine along the segment that passes through the project site has been agricultural, primarily for grazing and pasture. Typical constituents in runoff from pasture lands would include nitrogen, phosphorus, and coliform bacteria.

Stormwater runoff from urban development in the vicinity of the project site within the Markham Ravine is assumed to contain urban pollutants such as oil and grease, metals, nitrogen, and phosphorus from fertilizers, pesticides and herbicides, bacteria, and sediment. During average winter flow conditions, stormwater runoff from these urban areas are likely to contribute most of the constituents present in Markham Ravine, except for those constituents that are characteristic of agricultural or mining activities.[8] Recent collection of water quality data for the Orchard Creek watershed determined that the existing water quality meets the CVRWQCB basin plan for the Sacramento River and San Joaquin River.[9] While this is in a different watershed than Markham Ravine, it is, nevertheless, a good indicator of current water quality conditions in the City’s boundaries for urbanized creeks.

Groundwater

Near-surface soils in the project area consist of San Joaquin sandy loam.[10] The San Joaquin sandy loam is categorized as Hydrologic Group D soils over a cemented hardpan. The Placer County Flood Control and Water Conservation District (PCFCWCD) Stormwater Management Manual (SWMM) assumes infiltration rates ranging from 0.01 to 0.14 inches per hour for Group D soils, which is substantially less than permeable soils that provide greater recharge opportunity.[11] Soils with very low infiltration rates that overlie cemented hardpan limit infiltration of rainwater that can recharge underlying water-bearing strata and aquifers under normal conditions.

The project site is near the eastern boundary of the 351,000-acre North American sub-basin of the Sacramento Valley Groundwater Basin. Little or no groundwater flows into or out of the groundwater basin from the Sierra Nevada along the eastern edge.[12] Recharge areas for the aquifer system underlying the City of Lincoln generally are limited to local drainages, such as Coon Creek, Doty Ravine, Markham Ravine, Auburn Ravine, Ingram Slough, and Orchard Creek stream channels.[13],[14] Further, as noted in the project description, the site is not currently irrigated, so water is not returned to the underlying aquifer that would provide a source of recharge.

Project Specific Hydrology and Water Quality

The project site is located between residential developments and undeveloped land adjacent to the east side of the Gladding McBean Clay Plant and along the banks of Markham Ravine, west of East Avenue, north of Ninth Street extending north and west of the Carlin C. Coppin Elementary School. The site is undeveloped open space with grass cover. The proposed development site encompasses approximately 59 acres, and the proposed open space preserve area encompasses approximately 49 acres.

The Gladding Parkway project extends from Nicolaus Road, west of the Union Pacific railroad tracks to East Avenue and connects to SR 193 (McBean Park Drive). The future Gladding Parkway traverses the project site in an arc, from a point approximately 1,000-feet north of the southwest corner along the westerly boundary to the southeast corner at Ninth and East Streets. See Figure23 for the project layout and proposed Gladding Parkway alignment. Approximately 2,000 feet of the southeasterly portion of the Gladding Parkway project would be constructed within the project boundary.

Existing stormwater flows from off-site residential and commercial properties adjacent to the east and south project boundaries drain through the project site. The Drainage Report found archived City drawings that indicate five existing stormwater systems along the east and south boundaries. However, a visual inspection conducted for the Drainage Report of the area could locate only two of these systems. See Figure 4.3-2 for existing stormwater drainage systems and outfalls in the project site [NOTE TO REVIEWER: WILL CES OR GWD BE ABLE TO PROVIDE A CLEAR GRAPHIC THAT DEPICTS THESE FEATURES? GRAPHIC IN DRAINAGE REPORT IS TOO LARGE AND DETAILED TO INCLUDE IN THE EIR AS EVIDENCED BY THE ILLEGIBILITY OF THE REPRODUCED GRAPHIC]. {CESI Response: Please provide Exhibit #. CESI will provide an 11 X17 pdf of the required exhibit with any confusing background information removed.} There are four recorded stormwater outfalls that drain to the project site from the surrounding adjacent residential areas. These include:

·  an 18-inch stormdrain from 10th Street crosses East Street then discharges at a point between 9th and 10th Street (the location of this outfall has not been verified);

·  a 28-inch by 22-inch elliptical pipe discharges at the southeast corner of the property at East and 9th Streets;

·  a 12-inch stormdrain from B Street that discharges at an outfall on the north side of 9thStreet (the location of this outfall has not been verified); and

·  a 60-inch stormdrain conveys flows north along East Street from 11th to 12th Street, then west along 12th Street, south of the Coplin school to the southwest corner, then north along the west side of the school in an open field approximately 300-feet, then west approximately 340-feet to an open channel.