Atmospheric River Capture (ARC) Project - Information for the City of Novato by Marin Water

Information for the Novato Community

MarinWateris proposing to construct theAtmospheric RiverCapture Project, a watersupplyproject designed to improve reliabilityduring dryperiods.

Because portions ofthe proposed projectwould be located in and around the Novato citylimits, this fact sheet focuses onwhat the project could mean forthe community, including potential construction impacts, proposed facilities, and upcoming opportunities forinput as the environmental reviewprocess continues.

THE FULL PROJECT AT A GLANCE

New infrastructure would connect the North Marin Aqueduct to Nicasio Reservoir, allowing captured winter flows to be stored for use during dry periods.

The full Project would include a 13.2-mile pipeline, two pumping stations, a dechlorination facility and points of delivery at both Stafford Lake and Nicasio Reservoir.

*This connection to Stafford Lake creates a potential future opportunity for North Marin Water District to more efficiently capture and store available winter water during dry periods

FREQUENTLYASKED QUESTIONS

Because portions of the proposed project would be located in and around the Novato city limits, these FAQs focus on what the project could mean for the community, including potential construction impacts, proposed facilities, and upcoming opportunities for input as the environmental review process continues.

What to Expect in Novato

Whatshouldresidentsexpectduringconstruction?

Constructionwilllikelystartinlate2027-2028.Work wouldmovealongthepipelinealignmentovertime, meaningimpactswouldbetemporaryandlocalizedto specificsegmentsratherthanoccurringalongthefull routeatonce.

Becausemuchofthepipelinewouldbeinstalledwithin existingroadways,residentsmayexperiencetemporary disruptionsinareaswhereworkisactive Thesecould include:

Laneclosuresandtrafficdelays

Noiseanddustnearactiveworkzones

Temporaryparkingrestrictions

Temporaryaccesslimitationsnearconstruction

Detailedconstructionimpacts,includingtrafficand noise,willbeevaluatedaspartofthedraft EnvironmentalImpactReport(EIR).

WherewouldconstructionoccurinNovato?

WithinNovatocitylimits,theproposedARCProject wouldincludeapproximately35milesofnewpipeline, whichwouldgenerallybeconstructedwithinor alongsideexistingroadways,includingSanMarinDrive andashortsectionofNovatoBlvdnearSanMarinHigh School.Anewpumpstationwouldalsobeconstructed nearWoodHollowDriveintheSanMarinarea.The exactpipelinealignmentandconstructionapproachare stillbeingrefinedandwillbeevaluatedaspartofthe draftEIR.

Howwouldtrafficandaccessbemanaged?

Maintainingaccessforresidents,businesses,and emergencyservicesisakeyconsiderationofthe project.Whiledetailedtrafficcontrolplanshavenotyet beenfinalized,theprojectwill:

Maintainvehicleaccessduringconstruction, typicallywithworklimitedtoaportionofthe roadway(suchasasinglelanewherefeasible) Provideadvancenoticeoftemporaryparking restrictions(generallyatleast72hoursinadvance) Ensureemergencyaccessismaintainedatalltimes

Trafficmanagementstrategieswillbefurtherdeveloped andevaluatedaspartoftheEIR.

Howlongwouldconstructiontake?

PipelineconstructionwithinNovatoisexpectedtobe completedinroughly14to18months Workwould occurinsegments,withactiveconstructionprogressing alongthepipelinealignmentovertime.

Atalocalizedlevel,pipelineinstallationtypically advancesinsegmentsofroughly100to300feetper day,andsimilarcadencewouldbeexpectedforARC, meaningconstructionactivityinanyoneareawouldbe temporary.

Amoredetailedconstructionschedulewillbe developedastheprojectdesignadvances.

What happens to roads in Novato after construction is complete?

Any roadway or surface disturbed during construction would be restored following completion of the work, in accordance with City of Novato requirements Specific restoration approaches will be developed during final design and permitting, in coordination with the City The project team will work with the City to ensure roadway conditions are restored to equal or better condition following construction

Wouldconstructionnear Yes.Forareasnearschools School,SanRamonElemen Elementary,constructionti reducepotentialconflictsw workintheseareaswillbe monthsandotherlower-tra measureswillbeevaluated draftEIRandincoordinatio inNovato. WithinNovatoci approximately3.

xpectduringconstruction?

tinlate2027-2028.Work linealignmentovertime, temporaryandlocalizedto anoccurringalongthefull

newouldbeinstalledwithin smayexperiencetemporary workisactive Thesecould

cdelays iveworkzones rictions ationsnearconstruction

Howwouldtrafficandaccessbemanaged?

Maintainingaccessforresidents,businesses,and emergencyservicesisakeyconsiderationofthe project.Whiledetailedtrafficcontrolplanshavenotyet beenfinalized,theprojectwill:

cts,includingtrafficand partofthedraft ort(EIR).

onoccurinNovato?

heproposedARCProject ly35milesofnewpipeline, onstructedwithinor s,includingSanMarinDrive toBlvdnearSanMarinHigh nwouldalsobeconstructed theSanMarinarea.The dconstructionapproachare eevaluatedaspartofthe

Scale = 1:23,000

Created 5/18/26

PIPELINE CONSTRUCTION WITHIN CITY OF NOVATO

Trafficmanagementstrategieswillbefurtherdeveloped andevaluatedaspartoftheEIR.

Howlongwouldconstructiontake?

PipelineconstructionwithinNovatoisexpectedtobe completedinroughly14to18months Workwould occurinsegments,withactiveconstructionprogressing alongthepipelinealignmentovertime.

Atalocalizedlevel,pipelineinstallationtypically advancesinsegmentsofroughly100to300feetper day,andsimilarcadencewouldbeexpectedforARC, meaningconstructionactivityinanyoneareawouldbe temporary.

Amoredetailedconstructionschedulewillbe developedastheprojectdesignadvances.

Alignment A: 1 month

Alignment B: 10 months

Alignment B – near high school: 2 months (summer break of 2028 and/or 2029

Tie-in to NMWD Aqueduct: 1 month Pump Station: 2 years

Pipelineconstruc roadways,includ Similartootherp andgraduallypro fullrouteatonce

Howwouldtrafficandaccessbemanaged?

Facilities in Your Area

Maintainingaccessforresidents,businesses,and emergencyservicesisakeyconsiderationofthe project.Whiledetailedtrafficcontrolplanshavenotyet beenfinalized,theprojectwill:

Maintainvehicleaccessduringconstruction, typicallywithworklimitedtoaportionofthe roadway(suchasasinglelanewherefeasible)

Provideadvancenoticeoftemporaryparking restrictions(generallyatleast72hoursinadvance) Ensureemergencyaccessismaintainedatalltimes

Trafficmanagementstrategieswillbefurtherdeveloped andevaluatedaspartoftheEIR.

Howlongwouldconstructiontake?

PipelineconstructionwithinNovatoisexpectedtobe completedinroughly14to18months Workwould occurinsegments,withactiveconstructionprogressing alongthepipelinealignmentovertime.

Atalocalizedlevel,pipelineinstallationtypically advancesinsegmentsofroughly100to300feetper day,andsimilarcadencewouldbeexpectedforARC, meaningconstructionactivityinanyoneareawouldbe temporary.

Amoredetailedconstructionschedulewillbe developedastheprojectdesignadvances.

Working with the Novato Community

How is Marin Water coordinating with the Novato community on this project?

Marin Water is coordinating, and will continue to coordinate, with the City of Novato, County of Marin, North Marin Water District, and other local agencies as the project is developed. This includes working together on construction planning to help minimize disruptions, as well as identifying opportunities, where feasible, to align the project with local priorities and provide added community value. As more detailed information becomes available, the District will continue to share updates and provide opportunities for public input, including during the draft EIR public review period.

Wouldconstructionnearschoolsbeaddressed? Yes.Forareasnearschools,suchasSanMarinHigh School,SanRamonElementaryandPleasantValley Elementary,constructiontimingwouldbeplannedto reducepotentialconflictswherefeasible.Forexample, workintheseareaswillbescheduledduringsummer monthsandotherlower-trafficperiods.Specific measureswillbeevaluatedandrefinedaspartofthe draftEIRandincoordinationwithlocalagencypartners inNovato.

WithinNovatocitylimits,thepropose approximately3.5milesofnewpipelin nearWoodHollowDriveintheSanM

About the Project

Pipelineconstructionwouldgenerally roadways,includingportionsofSanM

Similartootherpipelineprojects,activ andgraduallyprogressalongthealign fullrouteatonce.

WithinNovatocitylimits,theproposedARCProjectwould approximately3.5milesofnewpipeline,alongwithapump nearWoodHollowDriveintheSanMarinarea.

Pipelineconstructionwouldgenerallyoccurwithinoralong roadways,includingportionsofSanMarinDriveandNovat

accessbemanaged? sidents,businesses,and keyconsiderationofthe afficcontrolplanshavenotyet ctwill:

essduringconstruction, mitedtoaportionofthe nglelanewherefeasible)

Similartootherpipelineprojects,activeconstructionwould andgraduallyprogressalongthealignment,ratherthanocc fullrouteatonce.

Project Status & Environmental Review

ceoftemporaryparking yatleast72hoursinadvance) ccessismaintainedatalltimes

tegieswillbefurtherdeveloped theEIR.

ructiontake?

hinNovatoisexpectedtobe to18months Workwould activeconstructionprogressing entovertime.

ineinstallationtypically roughly100to300feetper wouldbeexpectedforARC, tivityinanyoneareawouldbe

ctionschedulewillbe designadvances.

Photo from Nicasio Reservoir during 2020 drought

PROJECTTIMELINE

Estimated as ofJune 2026 and may change based on environmental review, property acquisitions and permitting.

2025-2026 Preliminary Design

2025-2027 Environmental Review

(Environmental Impact Report prepared in compliance with the California Enviornmental Quality Act)

Scoping: Initiate Environmental Review with Notice of Preparation (NOP) & Public Outreach Comments on EIR scope collected March 13 –Publish Draft EIR

KEY BENEFITS

Improve Drought Resilience

Captures excess winter water resulting from storm events, and stores it in local reservoirs for use during dry periods.

Address Public Comments on Draft and Publish Final EIR

Anticipated late 2026 / early 2027

2026-2027 Final Design & Permitting

2027-2030 Construction

Align with Community Priorities

Marin Water is coordinating with local agencies as the project develops to identify opportunities, where feasible, to align the project with local priorities and provide added community value.

Why Regional Water Supply Collaboration Matters

Drought Response (2021) – Residential Preparedness

During the most recent drought, Marin Water and North Marin Water District worked with the County of Marin and other partners to prepare for providing emergency potable water supplies for rural residents relying on wells that were at risk of running dry. These measures were ultimately not needed due to changing conditions.

Drought Response (2021) – Agricultural Use

Both water districts also worked with the County of Marin to support water needs in areas outside both districts’ service areas, including allowing West Marin ranchers to purchase and truck untreated reservoir water for agricultural use over several months during the drought.

Novato Landslide (2023)

A landslide in Novato raised concerns about access to local water supply. Marin Water coordinated with North Marin Water District and was prepared to support emergency interconnections if needed to help maintain service for North Marin Water District customers.

Future Opportunity – Stafford Lake Winter Water Storage

The ARC Project would include infrastructure connecting to Stafford Lake, creating a potential future opportunity for North Marin Water District to more efficiently capture and store available winter water during key storm events. By leveraging infrastructure used by both agencies, this could support additional drought resilience and more efficient use of available regional winter water sources.

Future Opportunity – Supporting North Bay Water Resilience

By allowing Marin Water to store water captured during key winter storm events for later use, the ARC Project could help reduce reliance on shared regional water supplies during droughts. This added flexibility may help support broader North Bay water resilience during periods when water supplies are limited.

The Atmospheric River Capture (ARC) Project is a water supply resilience project designed to improve Marin Water’s reliability during dry periods. It would provide the infrastructure needed to deliver high flows from the Russian River during and following key winter storms to Nicasio Reservoir for storage, where the water can be used later during dry periods.

HOW IT WORKS

From Storm to Storage

Even in dryyears with below-average rainfall, intense atmospheric river storms can temporarilyswell the Russian Riverwith high winter flows TheARC Project would operate during these dryyear storm windows to d otherwise flow to the ocean.

nter water captured during storm windows

Russian River watershed is much r than Marin Water’s Mt. Tam rshed. As a result, storms there can rate sustained runoff and elevated flows – even in dry years –ting opportunities to capture water.

vels through existing rth Marin Aqueduct

captured winter water would travel ugh existing infrastructure already by Marin Water Today, this water s directly to the distribution system, nto local reservoirs.

Conveyed to storage via new pipeline and pump system

The ARC Project builds a new connection between the Aqueduct and Nicasio Reservoir, providing the missing link that allows for captured winter water to be stored for later use.

red in Nicasio Reservoir for r use

ed water would supplement Marin er’s supply during extended dry ods. Diversions from the Russian r would be closely coordinated with her forecasts and reservoir levels would only occur when storage e is available and local conditions in Russian River Watershed allow