1 / 33

Hydrology Presentation

Yuba River Development Project FERC Project 2246 Relicensing. Hydrology Presentation. Thursday, November 10, 2010. Meeting Agenda. Introductions Previous Meetings Updated Hydrology Project Operations. Previous Meetings. 3/15/2011 – Conference Call Presented hydrology approach

tegan
Download Presentation

Hydrology Presentation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Yuba River Development Project FERC Project 2246 Relicensing Hydrology Presentation Thursday, November 10, 2010

  2. Meeting Agenda • Introductions • Previous Meetings • Updated Hydrology • Project Operations

  3. Previous Meetings • 3/15/2011 – Conference Call • Presented hydrology approach • Focus of discussion on accretions • Action items: • Investigate sources of difference between area-weighted and mass balance methods • Investigate more robust calculations of accretion flow • 4/28/2011 • Presented revised hydrology with precipitation adjustment to area weighted method • Showed how gage error could be used to explain difference between synthetic and mass-balance computed flows • Concerns remained about differences between synthetic and mass-balance computed flows • 5/15/2011 – Conference Call • Presented potential gaging error at Colgate and Smartsville as explanation for differences between synthetic and mass-balance flows. • YCWA indicated concerns about YB/DS unimpaired flows • Action Items: • YCWA to continue to evaluate potential sources of gaging error • YCWA to revisit analysis of unimpaired flow (hold discussions with R. Jones)

  4. Background YRDP Relicensing uses a mix of historical gaged flows and synthetic accretions. NBB accretion inflow is 33% of total NBB Inflow Englebright accretion inflow is 35% of total Englebright inflow (excluding NBB inflow)

  5. Background • Accretions are synthesized according to the formula: Flow1 = (Area1/Area2) * (Precip1/Precip2) * Flow2 • New Bullards Bar Reservoir accretions use both Oregon Creek and North Yuba near Goodyears Bar as index flows (Flow2) • Englebright Reservoir accretions use Oregon Creek as index flow • Precipitation based on PRISM 30-year annual average

  6. Area-Weighted Method Compared to Mass-Balance Method • Mass-Balance Method inherently must use downstream gage flow (Colgate or Smartsville) minus upstream gage flow in the calculation • Both Colgate gage and Smartsville gage are measuring about 3 times the flow volume that we are trying to synthesize. • Colgate gage + NBB storage change - upstream gages • Therefore, a X% deviation in gage measurement results in an 3X% deviation in computed accretion flow • A “good” USGS gage rating has an assumed measurement deviation of about 5% • Therefore for our use a “good” gage rating could result in a 15% deviation in accretion flow volume

  7. Comparison of New Bullards Bar Reservoir Accretion Calculation Methodologies

  8. Examination of NBB Mass Balance Differences between mass balance and synthesized flow are explainable by potential variations in gage data: Colgate PH gage variations • 1% 1971-1980 • 5% 1981-1994 • 6% 1995-2002 • 2% 2003-2010

  9. Correction of Colgate Gage Error • Study by Frank Lynch (formerly of PG&E) of acoustic doppler gages on Colgate penstocks. • Identified installation error affecting 10/2007-5/2011 • Revised flows included in mass-balance comparison • Corrected data submitted to USGS and incorporated in relicensing data

  10. Comparison of Englebright Reservoir Accretion Calculation Methodologies

  11. Examination of Englebright Mass Balance Looked at effect of potential gage variations at: Colgate gage- as described for NBB Smartsville gage- • 6% 1971-1977 • 8% 1978-1982 • 8% 1993-1994 • 2% 1995-2010 • No Oregon Creek data for 1996

  12. Middle and South Yuba River Unimpaired Flows • Disclaimer: • YRDP unimpaired flows were originally included on PIP Hydrology CD. • Unimpaired flows are not a part of hydrologic alteration or operations modeling • Background: • YB/DS published unimpaired flows at Jones Bar and Our House Dam as part of their Hydrology CD. • Comparison of those unimpaired flows with simulated unimpaired flows at Milton Diversion Dam, below Bowman Reservoir, and at Langs Crossing indicated an inconsistency in the downstream flow calculation • YCWA elected to compute accretions independently

  13. Unimpaired Middle Yuba River at Our House Dam • Uses unimpaired flow below Milton Diversion Dam from YB/DS • Synthesizes accretions between Milton DD and Our House Dam based on area-weighted precipitation adjusted flow method previously described, using Oregon Creek as the index watershed. • Double checked against available gaged accretions (10/1/1987-9/30/2007) • R2 = 0.87

  14. Unimpaired South Yuba River at Jones Bar • Uses unimpaired flow at Langs Crossing and below Bowman Reservoir from YB/DS • Computes accretions directly from USGS gages at Langs Crossing, below Bowman Reservoir, and at Jones Bar for full period of record.

  15. Accumulated Unimpaired Flow at Smartsville • Computed unimpaired Yuba River flow at Smartsville by adding: • Gaged North Yuba River flow at Goodyears Bar • Computed unimpaired Middle Yuba River at Our House Dam • Computed unimpaired South Yuba River at Jones Bar • Synthesized YRDP accretions above Englebright Dam • Compared to DWR published Full Natural Flow for the Yuba River at Smartsville (CDEC YRS) for 1976-2008

  16. Accumulated Unimpaired Flow at Smartsville

  17. Closer Look at Monthly Timeseries for Unimpaired Flow at Smartsville

  18. Now on to Project Operations • Overview of Yuba River facilities to be included in YRDP operations simulation • Slate Creek Diversion Dam (SFWP facility) • Our House Dam and Lohman Ridge Tunnel • Log Cabin Dam and Camptonville Tunnel • New Bullards Bar Dam and Colgate Powerhouse • Englebright Dam (USACE facility), Narrows 1 Powerhouse (PG&E facility), and Narrows 2 Powerhouse • Daguerre Point Dam (USACE facility) • YRDP operational drivers

  19. Yuba River Development Project Operations Model Coverage

  20. Slate Creek Diversion Dam • On Slate Creek (RM 8.8) • Owned and operated by SFWP • Not actively operated through most of the year • Minimum flow below dam • Currently 10 cfs • Varies monthly from 10-49 cfs under new license • Diverts to Slate Creek Tunnel • 600 cfs capacity

  21. Slate Creek Diversion Dam • Typically minimal active operation: • Only make changes when required by water right or FERC requirements • Two potential modes of simulated operation: • Use historical flows from gage below dam (USGS 11413300) • Compute inflows based on gage below dam and gage on tunnel (USGS 11413250) • Re-operate facility according to water rights and Slate Creek flow requirements • Ignore SFWP operations

  22. Our House Dam • On Middle Yuba River (RM 12.3) • Minimum flow below dam: • Varies monthly from 30-50 cfs • Releases made through a 24 inch dia. low-level outlet at base of dam (60 cfs capacity) • Diverts to Lohman Ridge Tunnel • 850 cfs capacity • Tunnel intake consists of a weir with a trashrack

  23. Our House Dam • Minimal active operation • Set low-level outlet according to downstream flow requirement • Flow above minimum flow requirement plus a buffer flows into Lohman Ridge Tunnel • Once Lohman Ridge Tunnel capacity is filled, remaining Middle Yuba River flows spill over Our House Dam

  24. Log Cabin Dam • On Oregon Creek (RM 4.2) • Around 100 feet below Lohman Ridge Tunnel outfall • Minimum flow below dam: • Varies monthly from 8-12 cfs • Releases made through a 18 inch dia. low-level outlet (13 cfs capacity) • Diverts to Camptonville Tunnel • 1,100 cfs capacity • Tunnel intake consists of a weir and a trashrack • Diverts flow into New Bullards Bar Reservoir

  25. Log Cabin Dam • Similar operations as Our House Dam • Low level outlet is set to meet downstream flow requirement • Flows above minimum flow into Camptonville Tunnel • Flows above Camptonville Tunnel capacity spill over Log Cabin Dam to Oregon Creek

  26. New Bullards Bar Dam and Reservoir • On North Yuba River • 966,000 acre-foot storage capacity • Up to 170,000 acre-feet of flood control reservation • Receives diversions from Camptonville Tunnel • Releases through: • Colgate Penstock (3,430 cfs capacity) • Low-level outlet (1,200 cfs limit) • Fish Hydro (6 cfs capacity • Spillway (167,000 cfs capacity)

  27. Colgate Powerhouse • On Yuba River (RM 33.5) • 5.8 miles below Middle Yuba River • Approx 1 mile above Englebright Reservoir normal maximum water surface • Twin pelton wheel turbines • 340 MW capacity (FERC nameplate is 315 MW)

  28. New Bullards Bar Dam and Reservoir and Colgate Powerhouse • Complex operations: • Flood management – Flood control reservation + downstream objective flows • Yuba River Accord – Lower Yuba River flow requirements • PG&E Power Purchase Agreement – Cooperatively manage reservoir storage and releases to provide power value • Target Storage operations (to be discussed) • FERC Requirements – Minimum flows on Middle Yuba, Oregon Creek, North Yuba River, and Lower Yuba River. Also ramping rates • Agricultural deliveries from diversions near Daguerre Point Dam • Water supply carryover storage targets

  29. Englebright Dam and Reservoir • USACE facility • Sediment management • Approximately 70 TAF of storage • Approximately 8,500 AF of storage currently exercised • Approximately 1.8 MAF of annual releases (WY 1970-2010) • Releases through Narrows 1 and 2 Powerhouses • Narrows 1 (PG&E): 720 cfs capacity • Narrows 2 (YCWA) 3,400 cfs capacity • Narrows 2 bypass (YCWA) 3,000 cfs capacity • Spill over dam crest • 181,000 cfs capacity

  30. Englebright Dam and Reservoir • Ensures relatively stable flows to Lower Yuba River • Elevations fluctuated to capture variability in Colgate Powerhouse releases • Releases to meet Lower Yuba River flow objectives • Flow requirements at Marysville and Smartsville • Agricultural deliveries from diversions near Daguerre Point Dam • Captures “freshets” from Middle and South Yuba rivers • New Bullards Bar Reservoir will reduce releases in anticipation of small storm events, creating space in Englebright. • Englebright storage exercised to manage small storm events through Narrows powerhouses • High volume of recreation usage • Minimum operational levels to protect marina operators

  31. Daguerre Point Dam • USACE facility • Debris management • No operable storage • Provides for gravity diversion for YCWA irrigation system

  32. Daguerre Point Dam • No operational capability • Site of diversions for agricultural deliveries north and south of the Yuba River • BVID’s Pumpline Diversion (.9 miles upstream) • Hallwood-Cordua Canal • YCWA Main Canal or South Canal • Approximately 116,000 acres currently irrigated from the Yuba River • Total build-out of approximately 120,000 acres • Approximate annual demands: • 310 TAF in wet years (331 TAF future) • 325 TAF in dry years (346 TAF future) • Annual contracts and water rights for 386 TAF • No historical shortages • Previous analyses imposed shortages to ensure sufficient storage to make minimal deliveries in following years assuming extreme drought conditions

  33. Next Steps • December: Meeting to discuss agricultural demands and detailed operations of New Bullards Bar and Englebright reservoirs • February-March: Meeting for initial release of operations model

More Related