Water Quantity in the Mid-Coast Region

Water Quantity Snapshot

 

Water quantity and water quantity management in the Mid-Coast region was summarized during Step 2 of the planning process. The entire report on water quantity can be accessed here.

  • Streams in the Mid-Coast have high streamflow during the winter months (January-March) and low streamflow during the summer/Fall months (August-October) as a result of seasonal precipitation patterns. 
     

  • Streams in the Mid-Coast are rain-dominated and responsive to precipitation, reaching high flows during rainstorms. Groundwater inputs maintain the base flows in streams during late summer and Fall months.
     

  • The Mid-Coast has eight active streamflow gage locations.
     

  • Information from river gages and water availability models help determine whether to issue new water rights. The water availability models take into account existing surface water and groundwater uses, and the amount of water available instream.
     

  • Generally, Mid-Coast groundwater is not very productive because of low permeability and low storage capacity of the regional rock formations.

Surface Water 

 

All of the major river drainages in the Mid-Coast, with the exception of the Yachats River, originate at the crest of the Coast Range in Polk and Benton Counties and extend to the coast. There are eight major river drainages in the Mid-Coast: the Salmon River, Siletz Bay-Ocean Tributaries, Siletz River, Depoe Bay-Ocean Tributaries, Yaquina River, Beaver Creek-Ocean Tributaries, Alsea River, and Yachats River. Many streams in the Mid-Coast are ocean tributaries, meaning that they drain directly into the ocean rather than draining to a river, and are tidally influenced. The zone of tidal influence in these streams depends on the discharge of the stream and the type of tide.

Water Providers by Population Served and Connections

There is a total of 52 water providers in the Mid-Coast region that deliver water to a total resident population of 60,877 people through 24,299 connections. The following bubble chart depicts the 11 major water providers in the Mid-Coast region that deliver water to a total resident population of 55,661 people via 22,391 connections. The first number under each provider is the resident population size; the second number is the number of water connections used to deliver the water supply.

ALSEA

  • Fall Creek Water District

BLODGETT

  • Bless Your Heart Baking and Cafe

  • Fir Ridge Campground

DEPOE BAY

  • City of Depoe Bay

GLENEDEN BEACH

  • Kernville-Gleneden-Lincoln Beach Water District

LINCOLN CITY

  • Lincoln City Water District

  • Oregon Parks and Recreation Department HB Van Duzer State Park

  • Lower Siletz Water System

  • Calkins Acres Improvement Inc.

NEWBERG

  • Sea Crest

NEWPORT

  • City of Newport

  • Oregon Parks and Recreation Department Ellmaker State Park

  • Oregon Parks and Recreation Department Beverly Beach State Park

  • Beverly Beach Water District

  • Otter Rock Water District

  • Bay Hills Water Association

  • Carmel Beach Water District

  • Lincoln County Parks - Moonshine Park

  • Mad Dog Country Tavern

  • Sawyers Landing RV Park

OTIS

  • Hiland WC - Echo Mountain, Boulder Creek, Bear Creek

  • Westwind Stewardship Group

  • Otis Junction Water system

  • Salmon River Mobile Village

  • Salmon River RV Park

  • Lincoln City KOA

  • Guptil Subdivision

OTTER ROCK

  • Johnson Creek Water Service

  • Inn at Otter Crest

REEDSPORT

  • US Forest Service Cape Perpetua Visitor Center

ROSE LODGE

  • Hiland WC - Riverbend​

SHERIDAN

  • Drift Creek Camp

SILETZ

  • City of Siletz

TIDEWATER

  • Hiland WC - Westwood

  • US Forest Service Blackberry Campground

TOLEDO

  • Toledo Water Utilities

  • Eddyville Charter School

  • Olalla Valley Golf Course

WALDPORT

  • City of Waldport

  • Kozy Acres Water System

  • Drift Creek Landing

  • Taylors Landing RV Park

  • Riverside Mobile Park

  • King Silver RV Park

  • Rovers RV Park

  • Happy Landing RV Park/Marina

YACHATS

  • Southwest Lincoln County Water PUD

  • City of Yachats

Instream Water Rights

 

In 1987, Oregon legally recognized instream uses as beneficial uses of water, allowing for the creation of instream water rights that authorize the use of water instream to protect aquatic ecosystems, and out-of-stream water rights to be transferred instream. Instream water rights protect a specified amount of flow be kept instream within a certain reach or at a specific point along a stream. They have a priority date, place of use, and rate just like any other water right. Typically, instream water rights allocate specified flows for each month in the year.

 

Oregon has three “families” of instream water rights.

  1. Instream water rights based on minimum perennial stream flows that OWRD administratively established in the 1950s and 1960s. 

  2. Instream water rights that state agencies, primarily the Oregon Department of Fish and Wildlife (ODFW),applied for after the passage of the Instream Water Rights Act, which have priority dates later than 1987 and are typically junior to many existing water rights. The beneficial use for these water rights is typically for maintaining flows for fish species, spawning, and migration. The Oregon Parks and Recreation Department (OPRD) and the Department of Environmental Quality (DEQ) are the other two agencies that can file for instream water rights for recreational purposes or pollution abatement.

  3. Instream rights that have been created through transferring an out-of-stream water right instream (such as an irrigation water right) or through the Allocation of Conserved Water Program. These instream rights are typically for small amounts of flow (1 cubic foot per second [cfs]or less), but may have senior priority dates.

Precipitation and Streamflow Variability

 

Streamflow in the Mid-Coast is extremely variable. Topography, soil conditions, ground cover, forest cover, geology, and land use all influence the discharge and timing of streamflow. Urbanization affects the amount and timing of streamflow by decreasing the ability of the land to absorb rainfall and causing runoff to reach streams quicker. During individual precipitation events, streamflow can increase quickly and significantly in some streams. Streams also exhibit diurnal fluctuations - streamflow varies between daytime and nighttime as the amount of evapotranspiration increases and decreases.

Streamflow also varies on a daily basis as a result of precipitation events. Shortly after rain begins, streamflow begins to increase. There is lag time between when rainfall is greatest and when streamflow is greatest because it takes time for rain to reach the stream. Instantaneous peak flow is the maximum discharge (flow) at a given time. Peak flows can be much higher than the 80 percent exceedance flows, which are the flows that can be expected 80 percent of the time based on a base period of record. More information about peak flows can be found using the Peak Discharge Estimation Mapping Tool

Streamflow Monitoring Locations


The Near Real-Time Hydrographics Database provides  recent data and information for streamflow gage locations in the mid-Coast whereas the Historical Streamflow and Lake Level Database provides historic and discontinued gage data.

© 2020 Oregon Mid-Coast Water Planning Partnership