NYWD Water – Domestic, Municipal, and Irrigation ( or “Where does our water come from?”)

This page only addresses the “where” of the water. I will address the question of “how much water?” and ” how do we pay for it” on a later page. I am also not talking about SFWP water intended for SFWP – I am only talking about NYWD water.

Please remember: I am still learning and will be updating these pages with new information as it becomes available. Science and research are always evolving as new data become available – these accounts are no different.

NYWD supplies domestic, municipal, and irrigation water. It is important to note:

A “water right” is a proprietary interest in the actual water, and is only granted by the State Water Resources Control Board. It is important to differentiate what kinds of rights are held. Any customer, inside or outside a District, has a “right to service,” not a “water right.” The Water District has a water right, not its customers.

I was asked multiple times during the campaign “where does our water come from?” Since this is part of what I do for a living, I researched, talked to people who worked for NYWD, and asked my map (GIS) scientist create an easy-to-read map of NYWD water flows. In the two maps below the yellow outlines show the routes, creeks, and facilities that move NYWD water from Point A to Point B and so on. Not all of the facilities belong to NYWD; some belong to South Feather Water and Power Agency (SFWPA). You can visit this page to see why: https://she-persisted.life/nywd-and-its-business-partner-sfwpp/

Municipal water service consists of water sales to other entities; for example, NYWD annually sells water to Yuba City.

Our (NYWD) water originates in the north from three sources: Little Grass Valley Reservoir, Slate Creek, and Lost Creek. Those are outlined in yellow on the map above. Water released from Little Grass Valley Reservoir comes down the South Fork Feather River and is diverted into Lost Creek through an underground tunnel (South Fork Power Tunnel). Water from Slate Creek is also diverted into Lost Creek through its own underground tunnel (Slate Creek Power Tunnel) as you can see in the map above. Where the two tunnels intersect Lost Creek, the waters from Slate Creek and South Fork Feather River (Little Grass Valley Reservoir) combine with the waters of Lost Creek (see above).

The combined waters of Lost Creek, Slate Creek, and Little Grass Valley (via the South Fork Feather River) flow south and are accumulated in Sly Creek Reservoir. The water there is released and it then flows into Lost Creek Reservoir. At the Lost Creek Reservoir Dam, another underground tunnel (Woodleaf Power Tunnel) conveys the water to SF-14 which is owned by SFWPA.

From SF-14, water can be directed one or both of two ways: west into the Woodleaf Penstock for power generation (which ultimately dumps back into South Fork Feather River) or south into the Forbestown Ditch. Water in the Forbestown Ditch is transported for both NYWD and SFWPA; in other words, we share the ditch. Recall however, on this page, we are only talking about NYWD water.

The Upper Forbestown Ditch System consists of the Upper Forbestown Ditch and the Oroleve Creek Ditch. The Upper Forbestown Ditch extends 10 miles from the Woodleaf Penstock outlet to the diversion into North Yuba Water District’s treatment plant reservoir. A diversion in Oroleve Creek supplies additional water to that which comes from the Woodleaf Penstock through the Oroleve Ditch to the Upper Forbestown Ditch.

Oroleve Creek Ditch – Up until the 2005 agreement, OWID (now known as SFWPA) owned the Water Rights to Oroleve Creek. The Oroleve Creek Ditch conveys water from Oroleve Creek to supplement SF-14 diversions. The water taken from Oroleve Creek is typically (at least since 1990) diverted in the late spring when the water is used to “season” the ditch by saturating the channel. OWID received permission in 1997 to construct a permanent concrete flashboard diversion structure in Oroleve Creek after heavy storm flows destroyed the previous excavated diversion. A condition of the permit is that Oroleve Creek could not be dewatered by the diversion when flows existed upstream. It also required a minimum flow to remain in the creek past the diversion from October 15 to June 15 each year for environmental purposes. In dry years the permit’s minimum flow requirement may prevent almost all Oroleve Creek water from being diverted into the Upper Forbestown Ditch System.

Language from the 2005 Agreement: SFWPA will transfer to YCWD, by quitclaim deed, and YCWD will accept, effective January 1, 2011, all of SFWPA’s right, title and interests in the Upper Forbestown Ditch, including all of SFWPA’s pre-1914 water rights in Oroleve Creek and in any other flows reaching the Upper Forbestown Ditch that have historically been diverted into the ditch and then transported by it.

Prior to 2010, the Upper Forbestown Ditch System was maintained by SFWPA with NYWD sharing 25% of the expense. In July 2010, in accordance with a 2005 agreement between NYWD and SFWPA, NYWD assumed ownership of the Upper Forbestown Ditch System and full responsibility for its operation and maintenance. At that time, SFWPA began receiving its allotment for the Lower Forbestown Ditch System at “WD-6,” which is a gauging station immediately below the diversion to NYWD’s treatment plant reservoir.

NYWD water in the Forbestown Ditch can then be diverted to: 1) the Forbestown Treatment Plant where it is treated for serving the domestic customers; or 2) Costa Creek which joins up with Dry Creek. South of Brownsville is a diversion gate on Dry Creek that can be opened to divert water into the Oregon House-Dobbins Canal to provide irrigation water to Oregon House and Dobbins. Dry Creek continues south to fill Collins Lake and Lake Mildred.

Water going to the Forbestown Treatment Plant supplies domestic water to the towns of Brownsville, Challenge, Cummings Ranch, Forbestown, Rackerby, and Sharon Valley. Untreated water exiting the treatment plant used to be released directly back into New York Creek feeding the water back into Dry Creek; however, it is now retained in a holding pond prior to release as required by the National Pollutant Discharge Elimination Systems (NPDES) permit. This is to allow the aluminum flocculent and other materials used to treat the water to settle out of solution prior to release back into the environment.

The Southern Portion

Valves, Gates, Turnouts, and Dams to Divert Water

Gauge WD-5: TBC

Gauge WD-6: A flow gauge on the Forbestown Ditch immediately downstream of the turnout from the Ditch to NYWD’s water treatment plant.

SF-14: We’ll start at SF-14 which SFWPA owns. SF-14 is a turnout on the Woodleaf Penstock through which water is conveyed from the Woodleaf Penstock into the Forbestown Ditch. A metered valve is present at SF-14.

Oroleve Creek Dam: A dam is present on Oroleve Creek to divert water into the Forbestown Ditch which is the primary water source for the Forbestown Treatment Plant that provides domestic water to many customers.

Costa Creek Turnout: When Dry Creek flows begin to decrease, the flow must be supplemented to maintain the supply of irrigation water to NYWD customers and to ensure that the flow in Dry Creek stays above 4 cfs as required by our permits. When water is needed to supplement the Oregon House-Dobbins Canal, the turnout from the Forbestown Ditch at Costa Creek is opened to allow water in the Forbestown Ditch to flow into Costa Creek which then drains into Dry Creek.

Dry Creek Diversion Gate: Dry Creek hosts a diversion gate south of Brownsville. The diversion gate diverts water from Dry Creek into the Oregon House-Dobbins Canal to provide irrigation water to Oregon House and Dobbins communities. Historically, the gate was opened April 1 to water up the system and ready it for water deliveries to begin April 15.

Water transported through SF-14 is used by NYWD for three primary reasons: 1) to maintain the reservoir levels at the Forbestown Treatment Plant for domestic customers; 2) to maintain flows to supply irrigation water to Oregon House and Dobbins irrigation customers; and 3) to maintain flows in Dry Creek at 4 cubic-feet-per-second (cfs) to support fisheries.

State permits bestowing water rights to Dry Creek on NYWD require the agency (see https://she-persisted.life/nywd-and-its-permits/) to maintain a flow of 4 cfs in Dry Creek for fishes. Creek flow is measured daily at the Dry Creek Diversion Dam. If flows drop below 4 cfs, NYWD requests water from SFWPA via the Forbestown Ditch. This requirement supersedes any irrigation water needs of the irrigation customers; in other words, that 4 cfs requirement has to be met first before irrigation water can be delivered.

Irrigation Water

Up until approximately May or June, NYWD irrigation water is supplied by Dry Creek only. (In other words, the Costa Creek diversion which opens up access to Forbestown Ditch water is not activated.) How long Dry Creek alone can provide irrigation water is dependent on weather; during very wet years, Dry Creek flows remain high well into summer and supplementary water from the Forbestown Ditch is not needed until later in summer. In dry years, Dry Creek may provide very little water and cannot meet the needs of NYWD irrigation customers nor the permit requirement of maintaining 4 cfs for fishes; thus, supplemental water from the Forbestown Ditch may be required very early in the season. Supplemental water from the Forbestown Ditch is obtained by opening the turnout at Costa Creek.

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