What is a Sensitive Area?

Chapter 8:3.5 of the Johnson County Unified Development Ordinance defines nine sensitive areas that are considered environmentally, culturally, or historically significant: 

Critical Wildlife Habitat

Areas identified as containing any species that are protected and identified by the Endangered Species List published by the United States Fish and Wildlife Service, or the Iowa Threatened and Endangered Species List published by the Iowa Department of Natural Resources.

Floodplain and Floodway

The floodplain is the land area susceptible to inundation by water as a result of a flood.

The floodway is the channel of a river or stream and those portions of the floodplain joining the channel, which are reasonably required to carry and discharge flood waters or flood flows so that confinement of flood flows to the floodway area will not result in substantially higher flood levels and flow velocities.

Historic Properties 

Areas containing significant information regarding the history or prehistory of the United States of America, the State of Iowa, and/or Johnson County.

Prairie and Prairie Remnant

An association of native grasses, sedges, and broadleaf plants. It includes areas of at least 0.3 acres in size that have at least 4 prairie grass species and 10 broadleaf plant species (with a coefficient of conservatism of 5 or greater in either Illinois or Missouri).

Savanna and Savanna Remnant

A mixed association of native trees in grassland (originally prairie but may now also have domestic grass). The native trees are open grown and are frequently oaks and hickories. For the purposes of Johnson County ordinance, it includes areas of at least one acre in size.

Significant Slopes

Landforms that contain slopes that are at high risk to erode, slide, or collapse. This includes protected slopes and critical slopes. Critical Slopes. Those landforms with a grade between twenty five percent (25%) and thirty five percent (35%).
Protected Slopes. Those landforms with a grade that exceeds thirty five percent (35%).

Stream Corridors, Watercourses, and Surface Water Bodies

A stream corridor is a river, stream or drainageway shown in blue (the blue line) on the most current U.S. Geological Survey Quadrangle Maps, and the area of its delineated floodway. In cases where no floodway is delineated, the blue line will serve as the centerline of a 30-foot wide stream corridor.  A watercourse is a river, stream, or drainageway that is not shown as a blue line on a U.S. Geological Survey Quadrangle Map. 

Wetlands

Those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. The diagnostic characteristics of wetlands are vegetation, hydric soils and hydrology.

Woodlands

An association of native forest trees such as those listed in Forest Trees of Johnson County by McBride, 1897. It includes areas of at least 2 acres in size.

Chapter 8:3.5 places protections on these areas of environmental concern and significant features, and outlines applicability of the regulations, impact limitations/guidelines, sensitive areas identification criteria, as well as sensitive areas report, waiver request, protection, and mitigation requirements.  

When is a Sensitive Areas Report Required?

All subdivision, Site Plan Review, and certain Conditional Use Permit applications are subject to Chapter 8:3.5.  Compliance with Chapter 8:3.5 must be illustrated via a Sensitive Areas Report. 

Subdivisions and Site Plans

Development applications for preliminary, combined, or final plat, and Site Plan Review must comply with the sensitive areas regulations, and submit a Sensitive Areas Report showing full compliance with Chapter 8:3.5 as part of the development application.  

Conditional Use Permits  

Conditionally permitted uses must comply with the sensitive areas regulations if required either by chapter 8:1.24 or as a condition of approval. No Conditional Use Permit which is subject to these regulations shall commence any site work until full compliance with Chapter 8:3.5 is demonstrated via a submitted, reviewed, and approved Sensitive Areas Report.

Grading Permits

All grading permit applications must comply with the sensitive areas regulations and submit a Sensitive Areas Report showing full compliance with Chapter 8:3.5 as part of the grading permit application.  No grading permit will issued without an approved Sensitive Areas Report or Sensitive Areas Waiver (see below).


No development application, Conditional Use Permit subject to 8:3.5, or grading permit will be approved or issued without an approved Sensitive Areas Report.

What is a Sensitive Areas Report?

A Sensitive Areas Report is used to illustrate full compliance with Chapter 8:3.5.  The report documents the assessment of the proposed development site for the existence of each sensitive area.  This includes supporting information such as datasheets, figures, exhibits, and photos. The boundaries of any sensitive area(s) identified on site and their buffers, as applicable, must be shown on an accompanying Sensitive Areas Plat Exhibit, per 8:3.5.B.1. 

Johnson County Property Information Viewer hosts publicly-available data, including environmental data layers, that can be used to aid preliminary assessment of a site for the presence of certain sensitive areas. Additionally, this resource can be used to generate supporting documentation to incorporate into a sensitive areas report.  When developing a sensitive areas report, please also refer to Chapter 8:3.5 for the most comprehensive guidance.  

Sensitive Areas Materials Required with a Development Application

Sensitive Areas Report

A digital copy, in addition to a single hard copy, of the Sensitive Areas Report must be submitted with the initial development application. 

Subsection 8:3.5.B.1 details the following report requirements: 

  • Must be developed by a qualified professional. 
  • Must include information used to make a conclusion on the presence or absence of a sensitive area. 
  • Must detail any proposed impact, including location, area, and reason for impact.  
  • Must include a detailed mitigation report if impact thresholds are exceeded. 
  • Must detail protection mechanisms for sensitive areas not proposed for impact. 
Sensitive Areas Plat Exhibit

If sensitive areas are present on a site, a Sensitive Areas Plat Exhibit must be submitted as part of the Sensitive Areas Report. Please refer specifically to subsection 8:3.5.1. 

Subsection 8:3.5.B.1 details the following exhibit requirements:

  • Must show the boundaries of each sensitive area and required buffers. 
  • Must show the boundaries of any proposed impacts.  
  • Must show the boundaries of any conservation easements. 
Mitigation Plan (as applicable) 

If impact to any sensitive area is proposed that exceeds mitigation thresholds, a complete mitigation plan must be submitted at time of development application.  Chapter 8:3.5. outlines the mitigation requirements for each individual sensitive area.

Subsection 8:3.5.B.4 details the following mitigation requirements:

  • Must be competed by a qualified professional.  
  • Must detail method of mitigation (e.g. off-site preservation, mitigation bank credits).  
  • Mitigation sites must be located in Johnson County.  
  • Must detail long-term protection standards, management, monitoring, and reporting. 
     
AutoCAD/GIS Data

If sensitive areas are present on a site, AutoCAD/GIS Data must be submitted to include, at a minimum, all sensitive areas, applicable buffers, and impact boundaries, as well as any established Conservation Easements or Limits of Disturbance.


Request for Waiver

Some development applications are eligible to request waiver of the sensitive areas requirements, and in such cases waiver may be granted if certain conditions as listed in subsection 8:3.5.A.6 are satisfied. If an application type is eligible to request waiver, a waiver request form must be submitted along with supporting documentation.

Requests must be made prior to filing a development application. If waiver is approved, the completed approved waiver request must be submitted with the development application. If a waiver is fully or partially denied - or if the waiver request only applies to a portion of the sensitive areas listed in section 8:3.5 - then a Sensitive Areas Report must be submitted with the application.

Sensitive Areas Waiver Request Form

Per subsection 8:3.5.A.6, the Zoning Administrator or a duly authorized representative may waive some or all of the requirements of this subsection for subdivision applications with 3 or fewer lots, grading permits, or for the commencement of conditionally permitted uses, if one of the following conditions are met:

a. It is clear upon cursory examination that no sensitive areas are present on site.
b. A sensitive areas analysis was previously performed on the property and the associated site plan and analysis are also adequate for the current proposed development or use.
c. For conditionally permitted uses: the duration, use, size, and impact of the proposed use will not adversely affect any sensitive areas or the preservation goals outlined in the Comprehensive Plan.
 

SENSITIVE AREAS WAIVER REQUEST FORM

Supporting Documentation

Johnson County Property Information Viewer hosts publicly-available data, including environmental data layers, that can be used to aid preliminary assessment of a site for the presence of sensitive areas.  Additionally, this resource can be used to generate supporting documentation to incorporate into a sensitive areas waiver request.  Further information for developing a waiver request with appropriate supporting documentation can be found here.  

 

Questions? Contact Planning, Development, and Sustainability at 319-356-6083.