POPULATION HISTORY AND PROJECTIONS

The first U.S. Census of Population, in 1850, reported Marion County’s population as 2,749. At that time, other Oregon counties reporting population were: Benton, 814; Clackamas, 1,859; Clatsop, 462; Linn, 994; Polk, 1,051; Washington, 2,652; and Yamhill, 1,512.

Historical population from 1900 for the State of Oregon, Marion County and the incorporated areas within the County is shown by Table No. 19. Figure 2 graphically shows the population growth trend of the County and the incorporated areas in the County and also the relationship between the two. In 1900, population within incorporated areas accounted for just 26.8 percent of total County population. By 1910, a major change had taken place in the amount of population residing within incorporated areas, with the figure at 50.6 percent. The incorporated population comprised 50 to 60 percent of the County’s population into the 1970s, but by 1980 the incorporated area supported over 70 percent of the residents. The fluctuation in the percentages is a function of the manner in which incorporations and annexations have taken place.

Table No. 19 (Updated to include 2000 Census Information)
Population History 1900 – 2000Oregon, Marion County, and Incorporated Areas Within Marion County

 

1900

1920

1940

1950

1960

1970

1980

1990

2000

Oregon

413,536

783,389

1,089,684

1,521,341

1,768,687

2,091,533

2,633,149

2,842,321

3,421,399

Marion County

27,713

47,187

75,246

101,401

120,999

151,309

171,700

230,028

284,838

Aumsville

171

174

281

300

590

1,432

1,650

3,003

Aurora

122

229

228

242

274

306

523

567

655

Detroit

206

328

367

331

262

Donald

126

164

187

201

231

267

316

612

Gates

189

250

455

499

471

Gervais

224

268

332

457

438

746

799

992

2,009

Hubbard

213

320

387

493

526

975

1,640

1,881

2,483

Idanha

442

295

280

319

289

232

Jefferson

273

417

479

636

716

936

1,702

1,805

2,487

Keizer

21,884

32,203

Mill City

1,289

1,451

1,565

1,555

1,537

Mt. Angel

537

936

1,032

1,315

1,428

1,973

2,876

2,778

3,121

St. Paul

160

183

226

254

346

312

322

354

Salem

4,258

17,679

30,908

40,087

45,245

62,960

89,233

107,786

136,924

Scotts Mills

208

227

217

155

208

249

283

312

Silverton

656

2,251

2,925

3,146

3,081

4,301

5,168

5,635

7,414

Stayton

324

649

1,085

1,507

2,108

3,170

4,396

5,011

6,816

Sublimity

172

280

367

490

634

1,077

1,491

2,148

Turner

289

414

610

770

846

1,116

1,218

1,199

Woodburn

828

1,656

1,982

2,395

3,120

7,495

11,196

13,404

20,100

Source: U.S. Census Bureau

Concentrations of population adjacent to incorporated areas may exist for a number of years before the area is either incorporated or annexed. By 2000, with the incorporation of Keizer, incorporated areas accounted for nearly 79 percent of Marion County’s population. This demonstrates that the percentages of incorporated population do not always reflect the true amount of urban population. The trend of total urban population growth will most likely be a constantly increasing percentage and will always be a higher percentage than incorporated population.

State Population Projections

The history of population growth in the State of Oregon reveals a steady increase in total population every decade from 1900 to 2000. Historic and projected State population is displayed in Table No. 20. The projections were made by the Oregon Office of Economic Analysis in 2004.

The significance of the State population is its magnitude and distribution. The majority of the State population is located in the Willamette Valley where most of the increase in population is occurring. The valley is expected to continue to receive the major share of the State’s population increases, putting a great deal of pressure on Marion County and its cities to provide for these new residents.

Table No. 20
Oregon Historic and Projected Population

Year

Population

Average Annual Growth Rate (%)

1940

1,089,684

 

1950

1,521,341

3.39

1960

1,768,687

1.52

1970

2,091,533

1.69

1980

2,633,156

2.33

1990

2,842,321

0.77

2000

3,421,399

1.87

2010

3,843,900

1.17

2020

4,359,258

1.27

2030

4,891,225

1.16

2040

5,425,408

1.04

Sources: 1940 – 2000, U.S. Census; 2010 – 2040 Oregon Office of Economic Analysis

County Population

The trend of continuous increase of total State population has been accompanied by continuous increases in total Marion County population, usually at a higher rate than achieved by total State growth.

Table No. 21 indicates that, like the State, Marion County is experiencing a large percentage of its population increase from in-migration. According to the population forecast prepared by the Portland State University Population Research Center, Marion County has experienced periods of higher and lower growth rates since the 1970s. Most recently, Marion County grew at a 2.2 percent average annual growth rate from 1990 to 2000 and a 1.3 percent annual growth rate from 2000 to 2008. The County is forecasted to grow to 410,245 persons in 2030, which is a 1.2 percent average annual growth rate from 2010 to 2030.

Table No. 21
Components of Marion County and State Population Change 2000 – 2007

Births

Deaths

Natural Increase

Net Migration

Total Increase

Percent Increase

Marion County

33,788

17,871

15,917

10,319

26,236

9.2

Oregon

333,500

221,506

111,994

212,062

324,056

9.5

Source: PSU Population Research Center 2007 Population Report

The Portland State University Population Research Center prepared County-wide and city population projections in 2008 at five-year increments through the year 2030. Marion County participated in a series of discussions with representatives of the cities to determine how the estimates for Marion County should be distributed. The population projections for Marion County and all its incorporated cities are shown in Table No. 22. The methods used to develop the preliminary projections were a combination of demographic and housing unit models, including a consideration of additional information provided by local jurisdictions.

Table No. 22
Population – Actual and ProjectedMarion County and Incorporated Areas Within Marion County

Jurisdiction

1990

2000

2007

20301

aagr 2010 2030

Marion County

228,516

284,834

311,070

410,245

1.20%

Aumsville

1,660

2,989

3,300

5,706

2.20%

Aurora

597

664

955

1,825

2.54%

Detroit

331

262

265

371

1.70%

Donald

314

607

995

2,034

3.20%

Gates2

466

437

460

487

0.23%

Gervais

999

1,923

2,250

4,597

2.80%

Hubbard

1,901

2,458

3,095

4,718

1.85%

Idanha2

160

131

145

170

0.63%

Jefferson

1,810

2,488

2,590

5,121

2.44%

Mill City2

309

316

328

367

0.53%

Mt. Angel

2,794

3,128

3,755

4,977

1.08%

Salem/Keizer UGB2

146,560

185,796

201,391

261,484

1.12%

St. Paul

322

352

410

556

1.34%

Scotts Mills

286

316

300

581

2.04%

Silverton

5,932

7,610

9,205

14,418

1.92%

Stayton

5,029

6,829

7,765

11,359

1.66%

Sublimity

1,487

2,139

2,255

3,200

1.53%

Turner

1,266

1,175

1,690

3,664

3.15%

Woodburn

13,535

20,191

22,875

37,216

2.04%

Unincorporated

42,758

45,023

47,041

47,394

0.19%

1 Forecast population

2 Marion County portion only. Estimates for the entire UGB of the following cities are provided for 2030: Gates, 550; Idanha, 279; Mill City, 1,792.

Sources: 1990 and 2000, U.S. Census Bureau; September 2008 Portland State University Population Research Center Population Forecasts for Marion County, Its Cities and Unincorporated Area 2010 2030.

These projections must be viewed as guesses about the future population in Marion County. These numbers may or may not be achieved at specified points in time. It is important, however, that as accurate as possible projections be made for each jurisdiction’s planning area to form a database for long- and short-range plans and implementing programs. These projections provide target dates for planners and decision makers to develop and implement the necessary programs to balance the various goals of the community. By programming community services and facilities according to levels of need at appropriate points in time, cost effective use of public and private funds can be improved.

The establishment and maintenance of 20-year projections for Marion County and the cities as shown in Table No. 22 are issued by the County to coordinate comprehensive plans and need to be reviewed and updated periodically. As actual growth rates change or new population studies are conducted and adopted, it is expected that these projections will be updated and new projections developed in coordination with the cities.

For Marion County and its five largest cities, scenarios were developed to provide a range of possible population projections depending on changing economic conditions, and other factors, that may affect migration into Marion County during the forecast period. The scenarios for Marion County in 2010, 2020 and 2030 are displayed in Figure 3. The scenarios for the five largest cities are provided in Table No. 23.

Table No. 23
Population RangesMarion County’s Largest Cities

Jurisdiction

1990

2000

2007

Range

20301

aagr 2010 2030

Keizer

21,768

31,890

35,435

Low

41,491

0.70%

Medium

49,486

1.48%

High

57,481

2.16%

Salem2

95,667

119,373

129,830

Low

152,562

0.74%

Medium

165,824

1.09%

High

179,586

1.42%

Silverton

5,932

7,610

9,205

Low

11,723

1.18%

Medium

13,052

1.57%

High

14,502

1.96%

Stayton

5,029

6,829

7,765

Low

10,053

1.15%

Medium

11,359

1.66%

High

12,721

2.13%

Woodburn

13,535

20,191

22,875

Low

34,272

1.69%

Medium

37,216

2.04%

High

41,718

2.53%

1 Population range under three growth scenarios.

2 Marion County portion only.

Sources: 1990 and 2000, U.S. Census Bureau; September 2008 Portland State University Population Research Center Population Forecasts for Marion County, Its Cities and Unincorporated Area 20102030.

Although projections were not developed for Polk County, scenarios for the Salem and Keizer Urban Growth Boundary were developed, which includes portions of Salem in Polk County and unincorporated areas of Salem and Keizer in both Marion and Polk Counties. These projections are presented in Table No. 24.

Table No. 24
Population RangesComponents of the Salem/Keizer Urban Growth Boundary

Jurisdiction

1990

2000

2005

Range

20301

aagr 2010 2030

Salem/Keizer Urban Growth Boundary

159,677

203,966

217,284

Low

275,449

0.9%

Medium

299,980

1.2%

High

324,929

1.6%

Salem

108,784

137,543

147,250

Low

187,905

0.9%

Medium

204,320

1.3%

High

221,257

1.6%

Keizer

21,768

31,890

34,735

Low

41,491

0.7%

Medium

49,486

1.5%

High

57,481

2.2%

UGB2

29,125

34,533

35,299

Low

46,053

0.9%

Medium

48,705

1.1%

High

52,903

1.5%

1 Population range under three growth scenarios

2 Area inside UGB and outside city limits of Salem and Keizer in Marion and Polk Counties.

Sources: 1990 and 2000, U.S. Census Bureau; September 2008 Portland State University Population Research Center Population Forecasts for Marion County, Its Cities and Unincorporated Area 2010 2030.

Urban Population

Projection of urban area population was made based upon the urban growth programs of each city in Marion County and the overall land use goals and policies of the State and County. Each community’s growth potential was analyzed using past growth trends and expected growth pressures in the future. Each community was consulted in developing these projections to coordinate city-County growth plans. These projections will help give perspective to the development pattern of Marion County by indicating the relationships among population centers. They will also provide guidance in updating of urban growth boundaries for each city. [Ord. 1291 § IV (Exh. B), 2009.]