POLK SOIL AND WATER
CONSERVATION DISTRICT
SOIL AND WATER 5 YEAR RESOURCE
CONSERVATION PLAN
June 2013
COMMISSIONERS ASSIST COMMISSIONERS
Dan Beougher Elaine Ilvess
Jane Clark Ray Meylor
Chip Mathis Louise Moon
Sherrie Taha Russ Paul
Cindy Valin Ryan Peterson
Lisa Walters
PREFACE
The Soil and Water Conservation District has responsibilities under state laws for carrying out a countywide soil and water conservation program. Planning for the long-term conservation of our soils, water, and related resources is not a simple task; but is a necessary process when orderly development and utilization of our natural resources is expected.
The Polk County Soil and Water Conservation District recognizes that with constant change, an operating strategy can seldom be long lasting and needs to be re-analyzed periodically. The update of our long-range program will reflect our objectives and priorities as we plan to meet the land and water needs of our people.
The commissioners of the Polk County Soil and Water Conservation District are providing this program for all individuals, groups, and units of government. It is an organized effort to protect our soil and water resources within the district. The second purpose is that the plan should be the focus of long-range development of the district’s soil and water resources, as well as the basis for budgeting and implementation. Furthermore, this continuous process is easily updated and/or amended to fit the needs of the citizens that the District serves.
The Polk County Soil and Water Conservation District commissioners appreciate the cooperation in developing this long-range plan. First the Commissioners would like to thank the representatives of the: Natural Resources Conservation Service (NRCS), Farm Service Agency (FSA), Iowa Department of Agriculture and Land Stewardship (IDALS), Division of Soil Conservation (DSC), Iowa Department of Natural Resources (IDNR), Iowa State University Cooperative Extension Service, County Board of Supervisors, Iowa Department of Transportation, U.S. Geological Survey, and the Iowa Department of Economic Development.
Secondly, credit should go to those contributing to the input that produced the objectives, goals, and priorities of this plan. These include: Polk County Conservation Board, Isaak Walton League, Ducks Unlimited, Pheasants Forever, Sierra Club, Audubon Society, Farm Bureau, Farmers Union, L.I.C.A. (Land Improvement Contractor Association), Contractors, Extension Service, Iowa Wildlife Federation, Farmers and other county REAP Committee members.
ORGANIZATIONS AND AUTHORITIES
The Polk County Soil and Water Conservation District was organized at the request of local people interested in soil and water conservation. A charter was issued under the provisions of the Code of Iowa, Chapter 467A (161A), on December 29, 1945. The boundaries of the district and the county are the same.
The district is a subdivision of state government, governed by five locally elected
commissioners, who are elected on the General ballot and serve four year terms.
District commissioners are charged by the Iowa General Assembly with the restoration and conservation of the soil, water, and related natural resources of the county. The district receives support services from the Iowa Department of Agriculture and Land Stewardship (IDALS). Commissioners can appoint as many assistant commissioners as they deem necessary.
Additional authorities have been given the soil and water conservation district since it was founded in 1945. Some of these additional authorities are:
1. Sub-districts, (Chapter 161A, Sec. 13-41), of a soil and water conservation district may be formed for the purpose of carrying out watershed protection and flood prevention programs, but shall not be formed solely for the purpose of establishing or taking over the operation of an existing drainage district.
2. The commissioners of the soil and water conservation district shall adopt reasonable regulations, (Chapter 161A, Sec. 42-53), to establish a soil loss limit or limits for the district and provide for the implementation of the limit or limits, and may subsequently amend or repeal their regulations as they deem necessary. Chapter 161A also provides for mandatory erosion control after due process.
3. The soil and water conservation district, (Chapter 161E), advises and consults with counties and sub-districts upon the request of any of them or any affected landowners, and is authorized to cooperate with other state subdivisions, or instrumentalities and affected landowners, as well as with the federal government or any department or agency thereof, to construct, operate, and maintain suitable projects for flood or soil erosion.
4. Under Chapter 161E, the County Board of Supervisors can establish districts having for their purpose soil conservation and control of floodwaters. The establishment of these districts requires the approval of the soil and water conservation district along with the Iowa Department of Natural Resources (IDNR). This section includes the role of the district in representing the rural as well as urban interests in the administration of the Erosion Control Law and other programs in which the district is involved.
The basic urban concern of the district is to help urban areas with erosion control. Consultative assistance is provided to both the cities and the county upon request. Also, these authorities are within the Code of Iowa, Chapter 161B - Agricultural Energy Management and Chapter 161C - Water Protection Projects and Practices. However, the ultimate responsibility for soil erosion control rests with the district.
District commissioners are authorized to request assistance from and enter into Memorandums of Understanding between themselves and other federal, state, and local entities to carry out their assignment and leadership role in the conservation, development, and productive use of the county’s soil, water, and related resources.
Active Memorandums of Understanding have been signed with:
U.S. Soil Conservation Service 5-25-46
U.S. Soil Conservation Service 9-19-49
IA Agricultural Extension Service 10-24-57
IA Agricultural Extension Service
and Home Economics 8-01-63
U.S. Department of Agriculture 1-26-65
Polk County Board of Supervisors 3-09-65
U.S. Soil Conservation Service 9-26-67
Central Iowa Regional Association of
Local Government 1-16-74
U.S. Army Corp. of Engineers 3-25-76
Skunk River Conservancy District 6-17-76
DSM River Conservancy District 6-17-76
Des Moines Schools 8-19-76
City of Des Moines 8-04-77
City of Polk City 7-17-78
U.S. Soil Conservation Service 7-19-82
U.S. Soil Conservation Service 6-16-87
Red Rock Resource Council 9-18-90
U.S. Soil Conservation Service 7-14-92
Polk County ASCS and CCC 7-15-94
U.S. Soil Conservation Service 11-4-96
U.S. Department of Agriculture
Food & Agriculture Council 4-15-05
The Polk SWCD has entered into the following 28E agreements:
Fourmile Creek Watershed Management
Authority 9-19-2012
The district also provides sponsorship and direction to programs administered by other agencies that directly affect the operations and objectives of the district. In addition, there are a number of agencies that have programs available that can assist the district in carrying out its long range program and annual plan of work.
GENERAL DESCRIPTION OF THE POLK COUNTY DISTRICT
The total area of the district is approximately 592 square miles or 378,800 acres. Roughly 96.6% of the total acres in the district are land, and the other 3.4 % is in water.
The north and east half of the district is mainly farmland. The majority of the prime farmland in the district is located in these areas. The City of Des Moines, which is located in the south central part of the district, is the location of many major companies. The State Capitol, as well as many other governmental agencies, is located in Des Moines.
The metro area, which includes the surrounding communities of West Des Moines, Urbandale, Clive, Ankeny, Johnston, Altoona, and Pleasant Hill, is the home for the majority of the people who live in the district.
The 2012 estimated population of Polk County is 443,710, an 8.5% increase since 2006. The demographics of the Polk County district can be divided into three distinctive groups. The first group is the percent of urban and rural people living within the district. Ninety-nine percent of the residents of the district live in incorporated areas, based upon the 2010 Census Bureau information. This then leaves one percent of the district’s population in a rural setting of which many are rural non-farms. The second group of our population is by percent of male and female. The population by gender in the district is 49.1 percent male and 50.9 percent female, and the percent of the district’s operating units that are male are 80 per cent, and female are 20 per cent. Thirdly, the district can be broken down by race percentages. The percentages show 80.5 per cent White (Not Hispanic), 6.2 per cent African American, 7.8 percent Hispanic/Latino, plus 4.3 per cent of others such as Asian American, Native American, and other Pacific Islander, etc. The district’s farm operating units are 98 per cent White, 2 per cent other such as African American, Asian American, and Latino. See the Appendix A for Census Bureau population charts. The median family income in the Polk County district is $57,473, which compares to the State average of $50,451.
Agricultural tendencies of the Polk County district have seen a decrease in the number of acres devoted to agriculture. The majority of the land in agricultural use produces corn and soybeans. The acres used for pasture have steadily declined. Many acres once used for pasture have been converted to other uses such as woodland, houses, or cropland. The acres being planted to woodland have held steady. Livestock numbers have declined. A majority of the cattle operations are located in the east part of the district and are cow-calf operations on pasture.
In recognition of the significance of healthy soils on soil retention, flood mitigation, moisture availability during drought conditions, and the retention and availability of nutrients such as N, P, and K for crop production and maintenance of clean lakes and rivers, a major focus of the Polk County Soil and Water Conservation District will be on improving soil and water quality. Over the last 5 years Polk County has experienced high rainfall and flooding for 2 years as well as one year of drought. The Polk district will focus efforts on installing practices over all landuses that improve soil health and quality as a way to manage water and the extreme weather conditions. The district has been promoting the installation of infiltration based practices as a way to manage stormwater in the urban landscape. The district will promote the use of no-till/strip-till and cover crops to improve our soils health and improve stormwater management and water infiltration in the rural area.
The number of acres within the district that are specifically used for row crops based on 2011 data is 171,000 acres or approximately 45 percent. Also, 25 percent of these acres are designated Highly Erodible Land under the Food Security Act. The following table shows the trend of major crops.
ACRES IN PRODUCTION
1956 / 1981 / 1989 / 2011Corn / 86,307 acres / 117,000 acres / 100,000 acres / 100,000 acres
Soybeans / 44,586 acres / 92,800 acres / 79,200 acres / 71,000 acres
Oats / 37,558 acres / 6,000 acres / 11,500 acres / 500 acres
Hay / 24,289 acres / 13,200 acres / 6,400 acres / 8,000 acres
TOTAL / 192,740 acres / 229,000 acres / 197,100 acres / 179,500 acres
The acres that are currently used for pasture are approximately 7,000. There are also 1,000 acres that are used to produce Christmas trees and other trees for sale. Another 500 acres are used to grow vegetables and over 300 acres of sod production.
Urban usage of land within the district is roughly 37.5 percent or 142,000 acres. This is the portion of land area designated as part of a town or city equal to or exceeding a population of 2,500.
Area with contracts in the Conservation Reserve Program (CRP) in the district is approximately 3.0 percent of the total cropland acres, or 4,878 acres. Currently there is 5,817 acres enrolled in the Wetland Reserve Program, Emergency Wetland Reserve Program, and the Emergency Watershed Protection Program.
Land use trends over the past 20 years have shown a shift of land from agricultural to nonagricultural uses. The urban expansion has occurred in the metro area surrounding Des Moines. The expansion has increased the greatest to the area west of Des Moines. However, the urban growth has also increased greatly around the Ankeny and Johnston area, and more recently around Altoona and Pleasant Hill. There has also been an increase in housing developments as well as single family acreages being built in the south and eastern rural part of the district. All of the development has converted land that once was used for agriculture. The Polk County Comprehensive Land Use Plan and Zoning Ordinances will guide future development. The Zoning Districts identified on the Zoning District map are designed to limit the development of prime farmland. A copy of the map is in the district office. See Appendix B for Article III County Ordinance on establishment of zoning districts and zoning map.
The major bodies of water include Saylorville Reservoir, Big Creek Lake, Dale Maffit Reservoir, Easter Lake, and Grays Lake. Major rivers and streams that follow through the district include the Des Moines River, Raccoon River, South Skunk River, Indian Creek, Big Creek, Beaver Creek, Walnut Creek, and Four Mile Creek. Of the above mentioned bodies of water, rivers, and steams, the Raccoon and Des Moines Rivers are used as primary sources of public drinking water. The other major sources of drinking water serving the district are rural water systems and private and municipal well water. The number and location of all private wells are unknown.
See Appendix C for a map of Polk County rivers, streams, and hydrologic units.
Ownership status of agricultural land within the district consists of two types. The first type of ownership is the land that is owned by the person who uses or lives upon it, which accounts for 33% of the land. The second type is land that is rented or leased to another party, which accounts for 67% of the land.
INVENTORY OF SOIL, WATER, AND RELATED NATURAL RESOURCES
SOIL RESOURCES
Frequent reference will be made to the existing Polk County Soil Survey, completed in
2000. It will be the source for much of the soils data presented throughout this section.
Soil Resources Used for Agricultural Production