Facts about drainage and drainage districts

1)  What is drainage? 

Drainage is the removal of water from the soil profile by natural or artificial means.  Drainage uses underground pipes and open ditches to carry water away from cropland during periods of excess moisture.


2)  What are drainage districts? 

Natural drainage outlets are not always available or accessible for all lands that need them in a particular watershed.  Use of a natural outlet that is adequate in capacity and depth to carry the runoff may require the extension of drainage outlets into land owned by others.  These other landowners may benefit from these types of extensions.  Similarly, a system of levees is often required to protect land from flooding.  Drainage districts provide a legally organized means to construct and maintain adequate drainage outlets and levees.  According to Iowa law – “The drainage of surface waters from agricultural lands and all other lands or the protection of such lands from overflow shall be presumed to be a public benefit and conducive to the public health, convenience and welfare.”


3)  How are drainage districts formed? 

Two or more contiguous landowners can petition the respective county Board of Supervisors to create a drainage district. 


4)  Who manages drainage districts? 

Iowa law is unique nationally on how this is done.  Once a district is created, the Board of Supervisors of the county in which the district is located becomes the board of trustees (managing board) for that district.  If a district chooses to do so, it can “opt out” of Board of Supervisor management and elect its own trustees.  Most districts are managed by Boards of Supervisors.


5)  Who pays for drainage districts? 

Lands within the confines of an established drainage district can be assessed for the construction, maintenance and repair of drainage district facilities.  Assessments are based on the relative benefits received and may be spread over several years. 


6)  How many drainage districts are there in Iowa and where are they located? 

 There are more than 3,000 districts in the state.  Most are located in north central and northwest Iowa although there are also districts bordering the Missouri and Mississippi Rivers. 


7)  How much of Iowa is drained land? 

It is estimated that more than 9 million acres of the state are drained.  That would constitute almost 26% of the state’s land mass.    9 million acres is larger than the combined land mass of the states of Massachusetts, Connecticut and Rhode Island.


8)  What is the Iowa Drainage District Association? 

IDDA is a private, non-profit organization existing solely for the benefit and protection drainage districts.  IDDA is incorporated with the state of Iowa.  Our federal non-profit tax status is 501 (c) 6.  IDDA is provided for in the Iowa Statutes Section 468.176. which states that “Levee or drainage districts are authorized to become members of drainage associations for their mutual protection and benefit, and may pay dues and membership fees therein out of their maintenance funds.”  


9)  Where in the Iowa Code are the drainage laws? 

The drainage statutes are quite extensive and cover almost 75 pages of the Code book.  The drainage statute is Chapter 468.  Also, the state apparently saw the importance of agricultural drainage early in the 20th century as there was language added to the constitution on drainage.  Article I, Section 18 of the Iowa Constitution states that “The general assembly, however, may pass laws permitting the owners of lands to construct drains, ditches and levees for the agricultural, sanitary or mining purposes across the lands of others, and provide for the organization of drainage districts, vest the proper authorities with power to construct and maintain levees, drains and ditches and to keep in repair all drains, ditches and levees heretofore constructed under the laws of the state, by special assessments upon the property benefitted thereby.   The general assembly may provide by law for the condemnation of such real estate as shall be necessary for the construction and maintenance of such drains, ditches and levees, and prescribe the method of making such condemnations.”  This constitutional provision was added in 1908.


10)  Do all drainage districts use gravity solely as a means for moving water? 

No, there are other districts in southeast Iowa by the Mississippi River that use an elaborate system of pumping stations.  These districts have their own section of the drainage laws.   By far the most prevalent systems however rely on gravity and the old axiom that water flows downhill.


11)  What about districts that have land in more than one county – how are they managed? 

In such cases, district management decisions would be made by both county boards of supervisors acting jointly.  In essence, the two county boards would become one for drainage purposes.  For ease of administration, a “lead” county is usually designated. 


12) How long have drainage districts been in existence?

Most of the drainage district statutes were written in the early 1900’s and the creation of many of today’s districts followed close behind that.  The long history of the districts is both a blessing and a disadvantage.  It is a blessing in that drainage of land has given us decades of productive agriculture that would not have been possible without it.  It is a disadvantage in that much of the drainage infrastructure is very old and will have to be replaced – at substantial cost to the landowners in the district.


Production and Environmental Benefits of Drainage