Impact Fee. A payment of money required from development as a condition of development approval to pay for capital improvements needed to serve new growth and development and is:

Impervious Surface. A non-vegetated surface area that either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development.  A non-vegetated surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving , gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater.  Open, uncovered retention/detention facilities shall not be considered as impervious surfaces for purposes of determining whether the thresholds for application of minimum requirements are exceeded.  Open, uncovered retention/detention facilities shall be considered impervious surfaces for the purposes of runoff modeling.

Impervious Surface Area. The land area of that portion of a lot covered by impervious surface.

Implementation, Transportation. The building, funding, operation, or regulation of a transportation facility, program, project and service.

Improvement, Transportation. An enhancement that has a beneficial impact on the level of mobility for people and goods, through the operation of construction of a transportation facility, program, project, and service.

Incidental (Use). Subordinate and minor in significance and bearing a reasonable relationship with the primary or principal use. (SMP)

Incremental Environmental Improvement. An improvement to a system protective of groundwater at an existing facility where the improvement reduces the facility’s impact on groundwater, provided the improvement is not one of the prohibited activities identified in RZC 21.64.050.C, Prohibited Activities in Wellhead Protection Zones.

Indirectly Illuminated Sign. A sign which is lighted by a source not seen directly.

Individual. An applicant, person, partnership, company, developer, party, firm, corporation, organization, or other human-created entity.

Infiltration. The flow of water into soil material. It is also used to describe the process of stormwater inflow into a sanitary sewer system. (SMP)

Inflatable Sign. Any sign and/or sign structure constructed of a canvas, rubber, or other light material capable of sustaining an inflated state for any period of time either through the use of gas or hot/cold air, the purpose of which is to aid the establishment in promoting the sale of products, goods, services or events, or to identify a building.

Infrastructure. Facilities and services needed to sustain industry, residential, commercial, and all other land use activities, including water, sewer lines, and other utilities, streets and roads, communications, and public facilities, such as fire stations, parks, schools, etc.

In-Kind Mitigation. Replacement of critical areas with substitute critical areas whose characteristics closely approximate those destroyed or degraded by a regulated activity.

Inlet. An underground structure that allows surface water to enter the storm drain system. Typically, it is a small catchless box-shaped structure with a slotted metal grate that does not contain a catch. (See Catch Basin.)

Integrity (Historic). A measure of the authenticity of a property’s historic identity evidenced by comparing its present state to its original unaltered state. This shall include whether the property has maintained its character by maintaining such things as original location, design, setting, materials, workmanship, or feeling and association.

Intentionally Created Streams. Streams created through purposeful human action, such as irrigation and drainage ditches, grass-lined swales, and canals.

Intermittent Stream. A stream that flows only part of the year after precipitation events and receives some water during that time from groundwater sources.

Internally Illuminated Sign. A sign whose light source is located in the interior of the sign so that the rays go through the face of the sign, or a light source which is attached to the face of the sign and is perceived as a design element of the sign.

Intersection. Where two or more public and/or private alleys, roads, streets, or commercial, industrial, or multifamily residential driveways meet or cross.

Investigation and Security Services. The provision of investigative and detection services, guard and patrol services, the picking up and delivery of money and other valuable items, or any similar service.

In-Water Structure. A structure that is typically associated with water-dependent uses and activities or that, by its nature, requires a location waterward of the ordinary high water mark of a stream, river, wetland, or lake. Examples of in-water structures include: a marina, residential dock, fishing pier, boat house, public boardwalk, car-top boat launch, motorized boat launch, swimming float, fish weir or ladder, and culvert. (SMP)