bucks creek hydroelectric project ferc project no. 619 · 2019. 9. 26. · forebay and lower bucks...

PACIFIC GAS AND ELECTRIC COMPANY

AND THE CITY OF SANTA CLARA

Bucks Creek Hydroelectric Project

FERC Project No. 619

Streamflow and Reservoir Level Gaging Plan

September 2019

©2019, Pacific Gas and Electric Company

and the City of Santa Clara

Bucks Creek Hydroelectric Project, FERC Project No. 619


September 2019 Page i Table of Contents




Bucks Creek Hydroelectric Project

FERC Project No. 619


TABLE OF CONTENTS

SECTION 1.0 INTRODUCTION........................................................................................ 1-1

1.1 Background .......................................................................................................... 1-1

1.2 Purpose of the Streamflow and Reservoir Level Gaging Plan ............................. 1-1

1.3 Objectives of the Streamflow and Reservoir Level Gaging Plan ......................... 1-1

1.4 Contents of the Streamflow and Reservoir Level Gaging Plan ............................ 1-2

SECTION 2.0 FLOW AND RESERVOIR LEVEL GAGE INFORMATION ............... 2-1

2.1 Streamflow and Reservoir Level Gages in Project Vicinity ................................. 2-1

SECTION 3.0 OPERATION AND MAINTENANCE OF FLOW AND

RESERVOIR LEVEL MONITORING GAGES ...................................... 3-1

3.1 Responsible Party ................................................................................................. 3-1

3.2 Data Quality ......................................................................................................... 3-1

SECTION 4.0 EXISTING DATA STORAGE AND DATA AVAILABILITY .............. 4-1

4.1 Internal PG&E Data Storage ................................................................................ 4-1

4.2 Publically Accessible Streamflow and Reservoir Level Data .............................. 4-1

SECTION 5.0 MODIFICATIONS OR CONSTRUCTION OF GAGES UNDER

THE NEW LICENSE .................................................................................. 5-1

5.1 Rating Curve Development .................................................................................. 5-1

5.1.1 Milk Ranch Creek below Three Lakes Reservoir .................................... 5-1

5.1.2 Milk Ranch Creek at Milk Ranch Conduit Diversion No. 1 .................... 5-1

5.1.3 South Fork Grouse Hollow Creek at Milk Ranch Conduit Diversion

No. 3 ......................................................................................................... 5-1

5.2 Structural Modifications ....................................................................................... 5-1

5.2.1 Bucks Creek below Bucks Lake Dam ..................................................... 5-1

5.3 Schedule ............................................................................................................... 5-2

SECTION 6.0 FLOW MEASUREMENT ASSOCIATED WITH SPILL

MANAGEMENT AT GRIZZLY FOREBAY AND LOWER

BUCKS LAKE ............................................................................................. 6-1



Table of Contents Page ii September 2019




SECTION 7.0 REPORTING AND PLAN REVISIONS ................................................... 7-1

7.1 Reporting .............................................................................................................. 7-1 7.2 Plan Revisions ...................................................................................................... 7-1

LIST OF FIGURES

Figure 1-1. Bucks Creek Hydroelectric Project Facilities ................................................ 1-3

Figure 2-1. Flow and Reservoir Gaging Locations .......................................................... 2-2

LIST OF TABLES

Table 2-1. Project-Related PG&E Flow and Reservoir Gages ....................................... 2-3



September 2019 Page iii Definitions




Definitions of Terms, Acronyms, and Abbreviations

For the purposes of this Plan, the following definitions apply:

TERM DEFINITION

A

ac acre

ac-ft acre-feet

C

CDFW California Department of Fish and Wildlife

CDEC California Data Exchange Center

cfs cubic feet per second

City City of Santa Clara

D

DWR California Department of Water Resources

F

FERC Federal Energy Regulatory Commission

FLA Final License Application

Forest Service U.S. Department of Agriculture, Forest Service

ft feet

H

HB Howell-Bunger

HYDSTRA Hydrologic Data Storage and Retrieval Software



Definitions Page iv September 2019




TERM DEFINITION

L

License Year A full calendar year, starting after license issuance (e.g., License Year

1 is the first full calendar year after license issuance)

Licensees Pacific Gas and Electric Company and the City of Santa Clara, joint

Licensees

N

NFFR North Fork Feather River

NFS National Forest System

P

PG&E Pacific Gas and Electric Company

Plan Streamflow and Reservoir Level Gaging Plan

PNF Plumas National Forest

Project Bucks Creek Hydroelectric Project, FERC Project No. 619

Project Boundary The boundary defined in the license issued by FERC for the Project

outlining the geographic area needed for Project operations and

maintenance.

Project Roads Roads within Project Boundaries and constructed for Project

purposes and necessary for Project operations and maintenance

S

SCADA Supervisory Control and Data Acquisition

sq mi square mile

SWRCB State Water Resources Control Board



September 2019 Page v Definitions




TERM DEFINITION

U

USFWS U.S. Fish and Wildlife Service

USGS U.S. Geological Survey

W

WSE Water-Surface Elevation



Definitions Page vi September 2019




This Page Intentionally Left Blank



September 2019 Page 1-1 Section 1.0




SECTION 1.0

Introduction

Pacific Gas and Electric Company (PG&E) and the City of Santa Clara (City), collectively the

“Licensees”, are filing with the Federal Energy Regulatory Commission (FERC) this Streamflow

and Reservoir Level Gaging Plan (Plan) in support of the Licensees’ Bucks Creek Hydroelectric

Project (Project), FERC Project No. 619. The Licensees are the owners of the Project; PG&E

operates the Project.

1.1 Background

The Project is located on Bucks, Grizzly, and Milk Ranch creeks, which are tributaries to the North

Fork Feather River in Plumas County, California (Figure 1-1). The Project has an installed

capacity of 84.8 megawatts and consists of two existing developments (Bucks Creek and Grizzly),

which collectively include four reservoirs with a combined usable storage capacity of

108,773 ac-feet (Bucks Lake, Lower Bucks Lake, Three Lakes, and Grizzly Forebay), one conduit

(Milk Ranch), two tunnels (Grizzly Forebay and Grizzly Powerhouse tunnels), two powerhouses

(Bucks Creek and Grizzly powerhouses), and associated equipment and transmission facilities and

structures, including recreation facilities and Project Roads.

Lands within the FERC Project Boundary are a combination of PG&E ownership and National

Forest System (NFS) lands (managed by the U.S. Department of Agriculture Forest Service (Forest

Service), as part of Plumas National Forest [PNF]). The Project Area also contains a small area

of private land.

1.2 Purpose of the Streamflow and Reservoir Level Gaging Plan

The purpose of this Plan is to describe how the Licensees document compliance with streamflow

and reservoir level requirements in the new FERC license.

The Licensees will coordinate, to the extent appropriate, the efforts required under this Plan with

other Project resource efforts, including implementation of other resource management plans and

measures included in the new license.

1.3 Objectives of the Streamflow and Reservoir Level Gaging Plan

The objectives of the Plan are to provide descriptions of:

Locations where the Licensees monitor compliance with the requirements in the

license related to streamflows and reservoir levels.

Equipment used by the Licensees to monitor compliance with the requirements in

the license related to streamflows and reservoir levels.

How data are retrieved from the equipment used by the Licensees to monitor

compliance with the requirements in the license related to streamflows and reservoir



Section 1.0 Page 1-2 September 2019




levels, including frequency of data downloads, quality assurance/quality control

procedures, and data storage.

How the Licensees make streamflow and reservoir level data available to FERC,

agencies, and the public.

1.4 Contents of the Streamflow and Reservoir Level Gaging Plan

Section 1.0 Introduction. This section includes introductory information, including

a general description of the Project; the purpose, goal and objectives; and the

organizational structure of the Plan.

Section 2.0 Flow and Reservoir Level Gage Information. This section provides

streamflow and reservoir level gage information.

Section 3.0 Operation and Maintenance of Flow and Reservoir Level Monitoring

Gages. This section describes existing streamflow and reservoir level gages.

Section 4.0 Existing Data Storage and Data Availability. This section describes the

Licensees’ approach to storing existing data gathered through the monitoring

network and how that data is made publicly available.

Section 5.0 Modifications or Construction of Gages under the New License. This

section describes the Licensees’ proposed changes to gages and data availability

under the new license.

Section 6.0 Flow Measurement Associated with Spill Management at Grizzly

Forebay and Lower Bucks Lake. This section describes Licensees approach to

collected stage and flow data during spill events.

Section 7.0 Reporting and Plan Revisions. This section describes how the Licensees

will report streamflow and reservoir level data to FERC, and update the Plan as

needed in the future.







Figure 1-1. Bucks Creek Hydroelectric Project Facilities







SECTION 2.0

Flow and Reservoir Level Gage Information

2.1 Streamflow and Reservoir Level Gages in Project Vicinity

Figure 2-1 shows the location of all Project-related PG&E gages. Table 2-1 provides information

for each gage regarding the gage name, location, period of record, and which gages are used to

document compliance related to streamflow, reservoir elevation, and down-ramping requirements.







Figure 2-1. Flow and Reservoir Gaging Locations







Table 2-1. Project-Related PG&E Flow and Reservoir Gages

PG&E Gage ID USGS No. Gage Name1

Approximate Location

Location Description

Gage Type and

Range

Data Collection and

Reporting3

License

Compliance

Period of Record

Latitude2 Longitude2 Start End

NF20 11403700 Bucks Creek Powerhouse,

near Storrie 39°54’39” 121°19’37”

Bucks Creek Powerhouse located on east

bank of the NFFR, approx. 0.2 miles

downstream of the Bucks Creek

confluence

Calculated,

Powerhouse Rating

Curve, full range of

flows

Continuous 15-min

collection

Manageable spill

ramping rates 1980-10-01 Present

NF22 11404300 Grizzly Creek below Grizzly

Diversion Dam 39°53’29” 121°17’35”

Gage and weir are located on Grizzly

Creek ~0.2 miles downstream of Grizzly

Forebay Dam

Weir and Water-

stage recorder,

standard rating below

GH 1.05 ft, above is

based on current

meter measurements

and Grizzly Forebay

spillway discharge.

Continuous 15-min

collection5

Instream flow

Channel

maintenance flow

Manageable spill

ramping rates

1985-09-30 Present

NF82 114035304

Bucks Creek below Bucks

Diversion Dam, near Bucks

Lodge

39°54’16” 121°13’47”

Lower Bucks Lake Dam low level outlet,

just upstream of the Howell-Bunger

valve

Ultrasonic flow

meter, full range of

flows

Continuous 15-min

collection Instream flow 1990-09-30 Present

NF108 11404240 Grizzly Powerhouse 39°53'21" 121°16'44"

In Grizzly Powerhouse located on north

shore of Grizzly Forebay near upstream

end of forebay.

Ultrasonic flow

meter, full range of

flows

Continuous 15-min

collection

Manageable spill

ramping rates 1993-10-01 Present

GR16 -- Grizzly Creek above NFFR N/A N/A Temporary, seasonal gage installed just

upstream of the NFFR confluence

Water-stage and

temperature recorder Intermittent-Summer

Water temperature

monitoring

MR16 -- Milk Ranch Creek above

NFFR N/A N/A

Temporary, seasonal gage installed just


Water-stage and


Water temperature

monitoring

BUCKS16 Bucks Creek above NFFR N/A N/A Temporary, seasonal gage installed just


Water-stage and


Water

temperature

monitoring

MR2 (new) Milk Ranch Creek below

Three Lakes Reservoir -- -- Three Lakes low level outlet valve. Rating Curve Manual measurement Instream flow -- --

MRC1 (new) --

Milk Ranch Creek at Milk

Ranch Conduit Diversion No.

1

-- -- Milk Ranch Conduit Diversion No. 1

sand trap valve Rating Curve Manual measurement Instream Flow -- --

MRC3 (new) --

South Fork Grouse Hollow

Creek at Milk Ranch Conduit

Diversion No. 3

-- -- Milk Ranch Conduit Diversion No. 3

sand trap valve Rating Curve Manual measurement Instream Flow -- --

BUCKS2 (new) -- Bucks Creek below Bucks

Lake Dam -- --

Upper Bucks Lake Dam low level outlet

HB valve, (new valve) Rating Curve Manual measurement Instream Flow -- --

NF11 11403450 Milk Ranch Conduit at Outlet 39°54’09” 121°13’36”

Stilling well and staff gage are located in

a sand trap approximately 200 feet

upstream of the conduit outlet.

Water-stage recorder,

full range of flows

Continuous, 15-min

collection 1969-10-01 Present

NF40 11404100 Bucks Creek Tunnel Outlet

near Storrie 39°53’03” 121°13’42” N/A N/A N/A 1976-10-01 1994-09-29







PG&E Gage ID USGS No. Gage Name1

Approximate Location

Location Description

Gage Type and

Range

Data Collection and

Reporting3

License

Compliance

Period of Record

Latitude2 Longitude2 Start End

NF10 11403300 Three Lakes Reservoir 39°58’05” 121°13’20” Staff gage is located on upstream face of

Three Lakes Dam.

Staff gage and

proposed new water-

stage recorder

Manual measurement

(Continuous, 15-min

collection upon

installation of water-

stage recorder)

Reservoir

Elevation

No data available

on line

NF12 114035303 Lower Bucks Lake Spillway 39°54’16” 121°13’47” Same as NF13.

Calculated, Spillway

Rating Curve, full

range of flows

Continuous, 15-min

collection

Channel

maintenance flow

Manageable spill

ramping rate

1990-09-30 Present

NF13 11403520 Lower Bucks Lake near

Bucks Lodge 39°54'16" 121°13'47"

Gage is located at outlet tower just

upstream of Bucks Diversion Dam. Water-stage recorder

Continuous, 15-min

collection

Reservoir

Elevation

1985-09-30 Present

NF16 11403500 (BCL7) Bucks Lake near Bucks

Lodge 39°53’45” 121°12’08”


upstream of Bucks Storage Dam. Water-stage recorder

Continuous, 15-min

collection4

Reservoir

Elevation

1928-10-01 Present

NF19 11404250 Grizzly (Forebay) Ck.

Diversion near Storrie 39°53’32” 121°17’25”


upstream of Grizzly Forebay Dam.

Water-stage recorder Continuous, 15-min

collection

Reservoir

Elevation

1986-09-30 Present

Notes: -- = Not Applicable

N/A = Not Available

1. Official USGS Gage Name, refer to Location Description column for spatial description of gage location.

2. Referenced to North American Datum of 1927 (NAD27)

3. Continuous flow data will be reported to the USGS as mean daily flows (i.e., 24-hour average). Intermittent water temperature data will be collected mid-June through mid-September and data reported as part of PG&E’s Rock Creek-Cresta Project (FERC No. 1962) Water Temperature

Monitoring Plan. Manual measurements will be collected when on-site for maintenance activities, and reported annually.

4. USGS gage represents the sum of NF12 and NF82. NFC12 is calculated by combining the flowmeter record from a gage located within the Bucks Diversion Dam low level outlet (NF82) with the Bucks Diversion Dam spillway discharge record (NF12), which is a calculated measurement

based on the Lower Bucks Lake gage height record (NF13).

5. Data will be upload to California’s Department of Water Resources (DWR’s) California Data Exchange Center (CDEC) website (https://cdec.water.ca.gov/)

6. Gages may be deployed as part PG&E’s Rock Creek-Cresta Project (FERC No. 1962) Water Temperature Monitoring Plan.

7. CDEC Site ID.







SECTION 3.0

Operation and Maintenance of Flow and

Reservoir Level Monitoring Gages

3.1 Responsible Party

Licensees own and operates all the gages listed in Table 2-1 that are used to document compliance

with minimum streamflows and reservoir elevations required by the FERC license. PG&E reviews

flow and elevation data daily via a Supervisory Control and Data Acquisition (SCADA) system

and its Hydrologic Data Storage and Retrieval Software (HYDSTRA) for operations and to ensure

compliance. PG&E verifies stage accuracy using a staff gage during site visits, and submits site

visit records to USGS for annual review. PG&E and USGS are each required to make a minimum

of two low-flow measurements per year to validate gage data.

3.2 Data Quality

PG&E and USGS provide data quality control. For the cross-listed PG&E and USGS gages listed

in Table 2-1, PG&E and USGS verify the stage-to-discharge relationship by making a streamflow

measurement every 4-6 weeks. Data logger gage height is verified with outside staff gages

monthly. Each year, a mean-daily flow summary station analysis and description, shift rationale,

gage height corrections, current meter measurement summary, field data sheets, datum

adjustments, rating tables, and hydrographs for the entire water year are submitted to USGS. Every

3 years, gage benchmarks, staff gages, point-of-zero flow, and water-surface elevation (WSE) are

surveyed to determine if there has been any movement in the reference elevations.

Gage data are processed and stored using HYDSTRA software. Rating tables are created in

HYDSTRA within the software program where HYDSTRA plots stage-to-discharge relationships

based on streamflow measurements made during stream gage rating checks on a log-log graph,

drawing a best-fit curve, and interpolating between graphical points on the curve. Manual

adjustments can be made to the software-derived rating curves by the hydrographer when needed.

New ratings are rare due to the stability of the concrete weir boxes and bedrock or boulder

dominated channels.







SECTION 4.0

Existing Data Storage and Data Availability

4.1 Internal PG&E Data Storage

Data are stored using the following methods:

Data loggers: Campbell Scientific CR1000 dataloggers are now used at most sites.

HYDSTRA: Long term storage for all data. This data is stored and backed up on

PG&E servers.

SCADA: Approximately 6 months to a year of data for all sites.

4.2 Publically Accessible Streamflow and Reservoir Level Data

Reservoir level data may be retrieved by the public from California’s Department of Water

Resources (DWR’s) California Data Exchange Center (CDEC) website for Bucks Lake, NF16

(CDEC Station ID BCL). Daily reservoir elevation (feet) and storage information (acre feet) are

automatically uploaded to the CDEC server. Data can be accessed at http://cdec.water.ca.gov/cgi-

progs/staMeta?station_id=BCL.

As part of the new License, and as soon as reasonably practicable within the first 90 days of the

new license term, real-time streamflow data will be made available to the public for the reach of

Grizzly Creek downstream of Grizzly Forebay Dam. The Licensees will provide hourly flow data

to the public from gage NF22 (USGS 11404300). The Licensees will make these flow data

available to CDEC (or at such time that CDEC is no longer viable, other similar entity that provides

publicly available flow information as agreed upon by Forest Service, U.S. Fish and Wildlife

Service (USFWS), California Department of Fish and Wildlife (CDFW), State Water Resources

Control Board (SWRCB), and Licensees).

In addition, by December 15 of each year, PG&E submits to USGS mean daily flow data for the

previous water year for the cross-listed gages. USGS typically reviews and certifies the data by

late spring of the following year. Certified historical mean-daily flow data and instantaneous peak

streamflow data for the entire period of record for each gage may be retrieved via USGS at

http://waterdata.usgs.gov/nwis/.

http://cdec.water.ca.gov/cgi-progs/staMeta?station_id=BCL

http://cdec.water.ca.gov/cgi-progs/staMeta?station_id=BCL

http://waterdata.usgs.gov/nwis/







SECTION 5.0

Modifications or Construction of Gages Under

the New License

Modifications to some existing flow sites and installation of new flow valves are needed to

adequately record the minimum stream flows associated with the Licensees’ proposed Project.

These modifications are described below.

5.1 Rating Curve Development

5.1.1 Milk Ranch Creek below Three Lakes Reservoir

The stream channel in Milk Ranch Creek below Three Lakes is not well defined and in some cases,

the flows go sub-surface in the rocky slope covering the face of the dam. To measure the

prescribed schedule of flows, the rating curve will be refined for the valve releases from the outlet

at the base of Three Lakes Dam.

5.1.2 Milk Ranch Creek at Milk Ranch Conduit Diversion No. 1

The stream channel below Milk Ranch Conduit Diversion No. 1 is not well defined and in some

cases, the flows go sub-surface. To measure the prescribed schedule of flows, a rating curve will

be developed and refined for the existing sand trap valve located at the diversion.

5.1.3 South Fork Grouse Hollow Creek at Milk Ranch Conduit Diversion No. 3

To release the prescribed flows, a rating curve will be developed and refined for the existing sand

trap valve located at the diversion.

5.2 Structural Modifications

5.2.1 Bucks Creek below Bucks Lake Dam

To release the minimum instream flow from Bucks Lake Dam, a Howell-Bunger Valve (HB

Valve) will be installed at the end of the existing low level outlet located at the base of Bucks Lake

Dam. Once installed, a rating curve will be developed and refined for the HB Valve to release the

prescribed flows.







5.3 Schedule

Where a flow measurement location must be modified or constructed, the Licensees will submit

applications for permits to modify or construct the facility as soon as reasonably practicable but

no later than License Year 2, and the Licensees will complete the work as soon as reasonably

practicable but no later than 2 years after receiving all required permits and approvals for the work.

During the period before facility modifications or construction are completed, and within the first

90 days of the new license term, the Licensees will make a good faith effort to provide the specified

minimum streamflows within the reasonable capabilities of the existing facilities.







SECTION 6.0

Flow Measurement Associated with Spill

Management at Grizzly Forebay and Lower

Bucks Lake

In accordance with the Spill Management at Grizzly Forebay and Lower Bucks Lake Measure

(PM&E WR-6), Licensees shall collect stage - discharge information to monitor spill conditions

in Bucks Creek downstream of Lower Bucks Lake Dam and in Grizzly Creek downstream of

Grizzly Forebay Dam.

As soon as reasonably practicable within the first 90 days of the new license term, a pressure

transducer (or similar stage measurement equipment) will be installed in Bucks Creek below

Lower Bucks Lake for the first five years of the license. Stage data will be downloaded periodically

and checked for accuracy. This stage data will be used in conjunction with the existing NFC12

flow record to analyze spill management on Bucks Creek.

Spill flows and stage in Grizzly Creek below Grizzly Forebay will be recorded at the existing

PG&E gage NF22.

Stage discharge information will be included with the final report, required by the Spill

Management at Grizzly Forebay and Lower Bucks Lake Measure (PM&E WR-6), after License

Year Five. This data will also be included, along with a brief summary, in the first Aquatic

Resources Monitoring Plan (PM&E AR-2) report following License Year Five. In the interim,

Licensees will provide stage-discharge information upon request.







SECTION 7.0

Reporting and Plan Revisions

7.1 Reporting

By January 31 of each year, the Licensees will file with FERC a streamflow and reservoir level

report. The report will include the following data for the preceding water year (October 1 through

September 30): 1) for each gage that monitors compliance with conditions in the FERC license,

flow and reservoir elevation data of appropriate time step in electronic format (i.e., on digital

versatile disk or similar format); 2) for ungaged locations, the dates the Licensees set the outlet

works/valves for each site based on water year type during the time the Licensees first accessed

each site (starting approximately in April) until November 1 (or until the winter setting was

established); and 3) a description of any deviations from the flow and reservoir level requirements

in the license.

7.2 Plan Revisions

The Licensees, in consultation with the Forest Service, USGS, USFWS, CDFW, SWRCB, and

interested stakeholders will review, update, and/or revise the Plan, as needed, when significant

changes in the existing conditions occur. Sixty days will be allowed for the Forest Service, USGS,

USFWS, CDFW, SWRCB, and interested stakeholders to provide written comments and

recommendations. After consultation and agreement with the Forest Service and SWRCB,

Licensees will work with the Forest Service and SWRCB to file the updated Plan with FERC. The

Licensees will include all relevant documentation of coordination and consultation with the

updated Plan filed with FERC. If the Licensees do not adopt a particular recommendation by the

USGS, USFWS, CDFW, or interested stakeholders, the filing will include the reasons for not doing

so. The Licensees will implement the Plan as approved by FERC.

bucks creek hydroelectric project ferc project no. 619 · 2019. 9. 26. · forebay and lower bucks...

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