Section 3702.20 Definitions

Section 3702

Section 3702.20  Definitions

"As-Built

Plans" A set of plans marked to show all deviations from the permitted

construction plans.

"Construct"

To erect, build, emplace, or remove a structure capable of storing or diverting

water.

"Corps Guidelines" The U.S. Army Corps of

Engineers' "Recommended Guidelines for Safety Inspection of Dams"

which is Appendix D of ER 1110-2-106, National Program for Inspection of

Non-Federal Dams, 33 CFR 222, as of July 1, 1983, not including any later amendments

or editions.

"Dam"

All obstructions, walls, embankments, or barriers, together with their

abutments and appurtenant works, if any, constructed for the purpose of storing

or diverting water or creating a pool.  Not included are underground or elevated

tanks to store water.

"Dam

Abutment" The intersection of the left or right side of the dam embankment

with natural ground surface.

"Dam

Height" Height of the dam in feet as measured from the natural bed of the

stream or water course at the downstream dam slope toe of the barrier to the

top of the embankment or barrier.

"Department"

The Illinois Department of Natural Resources.

"Director"

The Director of the Illinois Department of Natural Resources or his/her

designated representative.

"Drawdown"

The magnitude of the change in surface elevation of a lake or body of water as

a result of the withdrawal of water therefrom.

"Engineer"

A structural and/or professional engineer registered in the State of Illinois,

under the Professional Engineering Practice Act [225 ILCS 325] and the

Structural Engineers Act [225 ILCS 340], with expertise in the investigation,

design, construction, and operation of dams.

"Flood

Plain" The land adjacent to a body of water which has been or may

hereafter be covered by flood water.

"Freeboard"

The difference in elevation between the top of dam and the maximum water

surface that would be attained during the passage of the selected flood

occurrence

ural Engineers Act [225 ILCS 340], with expertise in the investigation,

design, construction, and operation of dams.

"Flood

Plain" The land adjacent to a body of water which has been or may

hereafter be covered by flood water.

"Freeboard"

The difference in elevation between the top of dam and the maximum water

surface that would be attained during the passage of the selected flood

occurrence.

"Impounding

Capacity" The total volume of water, expressed in acre-feet, that is

stored in the reservoir above the natural bed of the stream or watercourse when

the water surface is at the top of the  embankment or barrier.

"In

Conformance With All Applicable Standards Existing At The Time Of Its

Construction" Built in accordance with an Illinois Department of Natural

Resources, Office of Water Resources (or its predecessors) permit or having

written verification from the Department of a permit not being required.

"In Good

Repair" Maintained so as to be in sound condition, free from defect or

damage which may hinder the structure's functions as designed.

"Major

Modification" Major structural and/or hydraulic modification which

involves extensive reconstruction of a dam and/or its appurtenances.

"Normal

Pool" The water surface elevation corresponding to the elevation of the

principal spillway crest in the case of an ungated spillway, or the top of the

spillway gates in a closed position in the case of a gated principal spillway.

A dam may have more than one normal pool if operating procedures require

varying water surface elevations.

"OWR"

The Illinois Department of Natural Resources, Office of Water Resources.

"PMF"

The probable maximum flood.  The flood that may be expected from the most

severe combination of critical meteorologic and hydrologic conditions that are

reasonbly possible in a region.

"Qualified

Personnel" Federal or State personnel having the same experience as an

engineer.

"Rural

Areas" Areas of the State not classified as Urban Areas

of Natural Resources, Office of Water Resources.

"PMF"

The probable maximum flood.  The flood that may be expected from the most

severe combination of critical meteorologic and hydrologic conditions that are

reasonbly possible in a region.

"Qualified

Personnel" Federal or State personnel having the same experience as an

engineer.

"Rural

Areas" Areas of the State not classified as Urban Areas.

"Selected

Flood Occurrence" That flood occurrence which corresponds to the

recommended total spillway design flood for the particular classification of

dam as defined in this Part.

"This

Part" The Illinois Department of Natural Resource's Rules for

"Construction and Maintenance of Dams" (17 Ill. Adm. Code 3702).

"Urban

Areas" Areas of the State where residential, commercial or industrial

development currently exists or, based upon adopted or proposed land use plans

or controls, is expected to occur within ten years of the application date. In

determining urban areas, the expertise of local officials, regional or local

planning commissions, city and county planners, and private development

planners, as well as all available mapping may be utilized. Areas with isolated

or widely scattered buildings will generally not be classified urban areas.

"Urban

Development" The residential, commercial or industrial use of flood plain

areas, immediately upstream and downstream of a dam, excluding isolated farm

buildings.

"Watershed"

Total land area above a given point (e.g. a dam) on a stream or waterway that

contributes runoff to that point.

"Wave

Generation Height" The vertical distance between a crest and the preceding

trough of a wave caused by wind blowing over a water surface or caused by

mechanical methods such as waves generated by motor boats.