Forbestown Ditch Improvement Project
NYWD-03

I.  Project Sponsor Contact Information

Lead Agency/Organization / North Yuba Water District (District or NYWD)
Name of Primary Contact(s) / Jeff Maupin, General Manager
Mailing Address / P.O. Box 299 Brownsville, CA 95919
Email Address /
Phone / (530) 675-2703

II.  General Project Information

Project Title / Forbestown Ditch Improvement Project
Project Total Budget / $4,650,000
Project Funding Match / 0% - Disadvantaged Community (DAC)
Project Funding Request / $4,650,000 – though the project may be phased to accommodate a variety of budgetary restrictions.
Can a detailed cost estimate be provided upon request? / Yes
Latitude / 39 32’ 52” N
Longitude / 121 11’ 42” W
Could you provide a map of the project location including boundaries upon request? / Yes
County / Yuba/Butte
City/Community / Forbestown, Rackerby, Brownsville, Dobbins, Challenge, and Oregon House
Watershed/subwatershed / Project is located in the Yuba River Watershed. Project water is diverted from the South Fork of the Feather River via a penstock operated by the South Feather Water and Power Authority.
Groundwater Basin / Hard rock aquifer
Project Type / Facility Construction
Best Management Practices

III.  Project Description

The North Yuba Water District receives 100% of its potable water supply and a portion of its irrigation water supply through the Forbestown Ditch, a 10-mile long unlined, open ditch. This conveyance facility was originally constructed in the 1860s, and since that time has provided irrigation and domestic water to the residents in the communities of Forbestown, Rackerby, Brownsville, Dobbins, Challenge, and Oregon House. The service area is predominantly considered a disadvantaged community (DAC).

The Forbestown Ditch is in need of major repair/replacement and is subject to facility failures due to erosion. This project will replace the existing unlined ditch with a pipeline. The outcome of this conversion will include the following benefits:

·  Reduce water losses in the ditch. Current losses are approximately 50% of the water diverted at the intake, and are expected to drop to below 5% after ditch lining and pipe installation (the solution will likely be a combination of both of these practices). This will result in a savings of at least 4,120 acre-feet on an annual basis, and up to 7,620 AF.

·  Improve reliability of supply to the District water treatment plant. Extreme weather events including winter storms and fires have historically caused ditch outages. Conversion of the ditch to a pipeline with a complement of lined areas is expected to reduce these outages, saving water, agency staff time, and financial resources.

·  Improve water quality of the water delivered to the District treatment plant. Water quality of the open ditch can be affected by a variety of issues such as fires, spills, or local livestock grazing practices. This can result in issues such as high turbidity or bacterial contamination. Conversion to a pipe along the most sensitive and/or accessible areas of the waterway will reduce water quality impacts to the water supply.

·  Improve facility safety. The current ditch is accessible by the public and, in some areas, to a children’s summer camp. Conversion to a pipe in areas of public access will remove any safety issues that may be associated with an open ditch conveyance system.

IV.  Project Rationale/Issues Statement

The project addresses the following seven (7) issues:

  1. Infrastructure: This project will retrofit the 150-year-old ditch/flume system with a pipeline to provide an adequate and reliable water supply conveyance system for North Yuba Water District customers.
  2. Water Use Efficiency/Water Conservation: Currently the ditch loses approximately 50% of the water delivered at the ditch head gate. Modeling the system shows that ditch piping/lining will save 4,120 AF annually on the low end, and up to 7,620 AF on the high end on an annual basis. These losses include seepage from the ditch, surge flows required for conveyance that are unable to be used, spills caused by failures of the ditch banks, or other facility failure. Following ditch piping/lining, losses are expected to drop to less than 5%.
  3. Water Quality Contamination: The project will mitigate for contamination that could be caused by urban and agricultural run-off through piping the system. This will mitigate any issues regarding water quality impacts of local grazing or urban impacts as well as impacts from fires and severe winter storms. In addition, piping the ditch through populated areas will minimize the risk of wastewater infiltration via septic system seepage.
  4. Environmental Flows: By minimizing canal losses, more water can stay in the stream system, including the Feather River, Orleava Creek, and New York Creek. This will have positive effects on over all flows, as well as on temperature.
  5. Land Use and Land Conversion: Through lining the Forbestown Ditch, the NYWD will be better able to provide irrigation water at a consistent price and amount to irrigators in the Yuba watershed foothills. Currently, water management arrangements mandate that the NYWD pay power prices (upwards of $100/AF) for all water over 3,700 AF available at SF-14. This makes the water financially unavailable to the NYWD irrigators. In addition, canal capacity sometimes precludes agricultural deliveries. Piping of the canal will enable irrigators to obtain adequate water supplies at reasonable prices, allowing them to continue using the land for agriculture rather than selling it for development or other higher-value land uses.
  6. Regulatory Compliance: The State Water Resources Control Board is in the process of reviewing the extension of time for NYWD water rights and permits; a preliminary finding is that these extensions will be contingent upon implementing additional efficiencies in the Forbestown Ditch. NYWD rights will potentially be at stake without ditch lining.
  7. Climate Change: Adapting to climate change requires adding flexibility into water management systems. The impact in the Yuba Region will be on multiple levels, but includes decreased snowpack and increased demands for adequate instream flow in temperatures low enough to allow for fish survival. Through the lining of Forsbestown Ditch, the NYWD will achieve the following efficiencies and adaptive efforts:

·  Increased efficiencies in the watershed results in additional in-stream flows, generally lowering temperatures and allowing for greater habitat availability;

·  Increased instream flow also allows for additional power production capacity – more water going down the penstock means more water at the power plant; and

·  Lowering losses means that the same amount of water may be used to do more work.

All of these efficiencies lend themselves to increased flexibility in the face of climate change impacts.

V.  Goals/Objectives/Performance Metrics

Goals Addressed by the Project / Goal 1: The project will retrofit the existing aging water supply ditch to a pipeline to improve the sole water supply source for the NYWD.
Goal 2: The project will address contamination risk of the potable water source for the NYWD communities, including from septic seepage and overland flow into the Forbestown Ditch.
Goal 6: The project will improve water conservation through a decrease in water infrastructure water losses, therefore improving the District’s resiliency to climate change.
Goal 4: Adequate water at a reasonable price is essential for agricultural activity to continue in the region. This project will manage NYWD resources to allow for continued water supply to irrigation customers.
Goal 5: Drought preparedness requires efficiency; minimizing leakage in the Forbestown Ditch will allow for the NYWD to supply water of adequate supply and quality even in drought conditions – something that is currently not secure.
Goal 7: The majority of the area served by the District is considered a disadvantaged community (DAC).
Objectives Addressed by Project / Objective 1.1: The project will retrofit existing aging water supply ditch to a pipeline that will significantly increase reliability for the only source of water to the District. The existing ditch is subject to outages along side slopes and across wooden trestles, and is vulnerable to catastrophic wildfire and accidental contamination events from spillage and runoff.
Objective1.2: The project will greatly reduce water losses in the Forbestown Ditch from approximately 50% to less than about 5% with piping.
Objective 1.4: The project will improve disaster preparedness in the Region. The Yuba County Multi-Jurisdictional, Multi Hazard Mitigation Plan (Annex T) identified replacement of open ditches throughout the district with pipes as a Mitigating Action to reduce the affects of severe winter storms to the District. This will also improve water quality impacts to the potable water supply associated with catastrophic fires in the Region.
Objective 1.6: The project will significantly increase available water for agricultural uses in the District as a result of reduced leakage and increased capacity.
Objective 1.7: The District’s water rights mandate additional conservation on Forbestown Ditch.
Objective 2.6: Potable water quality must be protected, and encasing an otherwise open ditch addresses quality issues of sediment and overland flow, as well as accidental dumping at crossings.
Objective 4.5: Increasing Forbestown Ditch efficiency will allow NYWD to deliver water to irrigators even in times of great scarcity. Increasing efficiencies will decrease the amount of water the District must divert to get water all the way down the ditch and canal system to irrigators at the end of the line: this decreases costs associated with water purchase by both the District and the irrigators.
Objective 6.3: The project will improve the District’s resiliency to adapt to climate variability through a decrease in water loss in the ditch and increasing the reliability of the conveyance system to withstand extreme weather events. Climate variability could lead to a decrease in water availability. Groundwater in the Region is not readily available and therefore improvement of the surface water supply infrastructure is important to the District’s future resiliency to climate change.
Objective 7.1: The project will address water supply needs in a DAC and will increase the capacity of District staff to manage system losses and supply. Increased water consumption by the SFWPA has hurt the NYWD financially due to the District’s responsibility for all water losses along Forbestown Ditch. This financial drain is uncontrollable without ditch lining, and these losses drive the NYWD budget and manpower.
What performance metrics will be used to demonstrate that objectives are being met? Wherever possible, provide a quantitative measurement reflecting successful project outcomes. / Objective 1.1: Modeling the system shows that ditch piping/lining will save 4,120 AF annually on the low end, and up to 7,620 AF on the high end on an annual basis. In addition, these infrastructure upgrades will decrease maintenance requirements on the Forbestown ditch by more than 50%.
Objective1.2: As noted above, it is expected that at least 4,120 AF per annum of water supply will be conserved through installation of the pipeline.
Objective 1.4: The performance metric used will be implementation of planning efforts.
Objective 1.6: It is expected that approximately 3,328 AF per annum of water supply will be conserved during the agricultural season to allow for additional water to be sent to agricultural customers in the District.
Objective 1.7: The performance metric for meeting regulatory requirements will be met by additional conservation and diversion point versus WTP metering to check losses.
Objective 2.6: The metric for this objective will be the covered portions of the ditch in areas of increased risk to quality.
Objective 4.5: Increased water quantity availability to irrigators during drought years.
Objective 6.3: The performance metric used will be implementation of the project.
Objective 7.1: Completion of this project in the DAC region served by the NYWD will be the performance metric for this objective.

VI.  Resource Management Strategies

Reduce Water Demand
Agricultural Water Use Efficiency / Increase water use efficiency through a decrease in water losses in the Ditch that supplies water for agricultural use.
Urban Water Use Efficiency / Increase water use efficiency through a decrease in water losses in the Ditch that supplies water for urban use.
Improve Operational Efficiency and Transfers
Conveyance—Regional/Local / Increase water use efficiency supplying urban and agricultural water users.
Improve Water Quality
Drinking Water Treatment and Distribution / Piping the open ditch will improve water quality through decreased turbidity and decrease contamination from local agricultural or other contamination sources.
Pollution Prevention / Lining key areas of the Forbestown Ditch will minimize the risk to potable water source for the NYWD.
Urban Runoff Management / Piping the ditch in key areas will minimize the contamination potential of urban runoff and septic seepage into the currently unlined ditch.
Practice Natural Resources Stewardship
Agricultural Lands Stewardship / Increasing the efficiency of Forbestown Ditch will steward the continued use of land in the NYWD for agriculture though allowing water to flow down the ditch for agricultural uses in a broader array of years (including drought years such as this one).

VII.  Statewide Priorities

Drought Preparedness

§  Promote water conservation, conjunctive use, reuse and recycling

§  Achieve long term increase in available water supply from leakage reduction

§  Achieve long term increase in available water supply from leakage reduction

Use and Reuse Water More Efficiently

§  Increase urban and agricultural water use efficiency measures such as conservation and recycling

Climate Change Response Actions

§  Adaptation to Climate Change: Use and reuse water more efficiently

§  Adaptation to Climate Change: Water management system modifications that address anticipated climate

Protect Surface and Groundwater Quality

§  Protecting and restoring surface water and groundwater quality to safeguard public and environmental health and secure water supplies for beneficial uses

Ensure Equitable Distribution of Benefits

§  Increase the participation of small and disadvantaged communities in the IRWM process

§  Develop multi-benefit projects with consideration of affected disadvantaged communities and vulnerable populations

§  Contain projects that address safe drinking water and wastewater treatment needs of DACs

Climate Change Adaptation
The North Yuba Water District is located in the foothills portion of the Yuba Region, which is underlain by a fractured rock aquifer. This aquifer may, at best, yield small quantities of water to an individual well. The District therefore relies on surface water as its sole source for water supply. To improve its resiliency to climate change, this project will replace an unlined ditch subject to approximately 50% water losses with a pipeline that is expected to result in water losses of less than approximately 5%. This allows the District to maintain their current level of service to customers with a decrease in consumptive water use. Reducing consumptive water use improves resiliency to climate change variability, the effects of which may decrease availability of surface water through decrease in snowpack and increase in flash precipitation events.