The Nevada State Legislature has, in chapter 278 of the Nevada Revised Statutes, delegated to local governing bodies the authority, power and responsibility to promote the public health, safety, morals and the general welfare of the community by regulating and restricting the improvement of land and by controlling the location and soundness of structures (Nevada Revised Statutes 278.020). It is the intent of the legislature that such regulation, restriction and controlling be accomplished through a system of comprehensive planning, zoning, subdivision regulations, planned unit development regulations, parcel map regulations and building regulations (Nevada Revised Statutes 2781.150, 2781.160, 2781.230, 2781.326, 2781.349, 2781.380 and 2781.462; and 278A).

The legislation specifically provides that flood hazards and drainage must be considered. (Nevada Revised Statutes 278.160[1][b] and [h], 278.250[2][d], 278.340[3][h] and 278.462 [1]; and 278A.270).

The local governing body may set conditions for approval of tentative subdivision maps (Nevada Revised Statutes 278.349[1]), may accept dedications and easements and may require that the subdivider improve or agree to improve easements (Nevada Revised Statutes 278.380).

The local governing body may require drainage provisions as a condition of approval of parcel maps (Nevada Revised Statutes 278.462[1]).

The local governing body may adopt a building code specifying the design of structures (Nevada Revised Statutes 278.580[1]) and it may withhold building permits as a means of enforcing the zoning regulations (Nevada Revised Statutes 278.570[1]).

(Ord. 841, 2-23-1988, eff. 3-23-1988)

A.

The City is situated partly in the flood plain of Hemenway Wash and its tributaries which drain into the Colorado River, and partly on alluvial cones which drain to the Eldorado Valley "Dry" Lake. Both the flood plain areas and the alluvial cone areas have been subjected to repealed inundation, erosion and deposition of sediment, resulting in hazard to life, damage to property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare.

B.

These flood losses are caused by:

1.

Natural patterns of flood runoff resulting from high intensity rainfall.

2.

Urbanization which has increased the rate and volume of storm runoff.

3.

Obstruction of flow paths by various urban improvements.

4.

Collection and concentration of flows on the alluvial cone by highway and railroad construction.

5.

Lack of an adequate comprehensive storm drain and flood control system to control erosion and sedimentation, collect storm runoff and carry it safety through the City.

6.

Inadequately anchored structures.

C.

Special flood hazard areas in the City have been identified by the United States Federal Insurance Administration (U.S.F.I.A.) under the National Flood Insurance Program (NFIP) and are shown on the City's Flood Insurance Rate Map (FIRM). These special flood hazard areas are based on the 100-year flood, with watershed development conditions as they existed in 1979 and without consideration of erosion and sedimentation. As urbanization continues to increase the rate and volume of storm runoff, and as long as erosion and sedimentation remain as components of the flood problem, the FIRM will understate the extent and degree of the flood problem.

D.

Drainage area boundaries on the alluvial cone are indistinct. Under natural conditions of erosion and sedimentation, flow paths may vary from one storm to the next. Without clear, stable drainage area boundaries, it is impossible to proceed with drainage planning, establish development requirements or design flood control projects.

E.

A massive conventional gravity flow urban storm drainage and flood control system adequate to control erosion and sedimentation, collect storm runoff, carry flood flows safely to an adequate point of discharge and protect the lives and propertyof the citizens of the City would require massive disruption of the community, relocation of utilities, construction of bridges, condemnation of right of way, and removal of residences; and would require an unreasonable financial commitment.

F.

A flood damage prevention system based upon the concept of temporary detention of storm runoff where appropriate can be implemented as an integral part of the development process, at a cost far below that of a channelization system, and with a minimum of community disruption. Such a system would assure that future new developments are safe from flood hazard and do not increase the hazards to adjoining or downstream properties. Eventually, such a system would reduce or eliminate the existing flood hazard to many downstream developed areas.

G.

The continuing effectiveness of any flood damage prevention system requires adequate maintenance by a public agency. An adequate and stable financial base must be provided to support continuing maintenance activities.

H.

A comprehensive program of flood damage prevention, which addresses the need to regulate future development and to secure solutions to existing flooding problems, must call into play many sectors of City government. To provide direction and policy guidance, it is necessary to have a drainage master plan, which contains future development projections, drainage area boundaries, level of protection, project concepts, project plans and drainage standards and criteria for public works and private developments.

I.

Federal regulations for the NFIP require that as a minimum the City must adopt the Federal flood plain management requirements as a condition for remaining in the NFIP. Participation in the NFIP is a requirement to remain eligible for flood insurance for property owners, mortgage funds in special flood hazard areas and Federal grants-in-aid for any activities in special flood hazard areas. The flood plain management provisions of this Chapter satisfy the Federal requirements.

(Ord. 841, 2-23-1988, eff. 3-23-1988)

It is the purpose of this Chapter to:

A.

Meet the requirements of NFIP, thus assuring the availability of flood insurance to City residents and businesses and continuing the availability of mortgage funds and grants-in-aid in designated special flood hazard areas.

B.

Promote the public health, safety and general welfare, and minimize public and private losses due to flood conditions by provisions designed:

1.

To protect human life and health.

2.

To minimize expenditure of public money for costly flood control projects.

3.

To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public.

4.

To minimize prolonged business interruptions.

5.

To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in areas of special flood hazard.

6.

To help maintain a stable tax base by providing for the safe use and development of areas of special flood hazard so as to minimize future flood blight areas.

7.

To ensure that potential buyers are notified that property is in an area of special flood hazard.

8.

To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.

C.

Provide for a master plan of drainage and a comprehensive program throughout City government aimed at reducing and preventing flood damages through planning, zoning, subdivision, administration, building permit administration, capital projects, maintenance and public information.

D.

Accomplish the detention of storm runoff where appropriate in new developing areas, thus assuring the safety of future residents of such areas, and also eventually eliminating or reducing downstream flood hazards.

E.

Maintain the natural radial flow path of runoff on the alluvial cones, thus avoiding concentration of flood flows directed at developed or developing areas of the City.

F.

Provide the criteria and standards to resolve existing drainage problems which may not be affected by the detention strategy.

G.

Reduce City flood-related costs.

H.

Provide a basis for practices and procedures to be implemented by the City departments responsible for public works and regulation of development, including planning, zoning, subdivision and building administration.

I.

Clarify City development requirements for landowners and developers.

J.

Ensure that new private residential and nonresidential development is reasonably free from flood hazard due to inundation, erosion and deposition of sediment, and does not increase the hazard to adjoining property by increasing flood heights, deflecting flows or causing erosion or sedimentation.

(Ord. 841, 2-23-1988, eff. 3-23-1988)

In order to accomplish its purposes, this Chapter includes methods and provisions for:

A.

Establishing a master plan of drainage which:

1.

Identifies all sources of flooding affecting the City and all drainage patterns.

2.

Establishes drainage area boundaries.

3.

Establishes levels of protection.

4.

Establishes engineering criteria and standards for regulation of development and design of drainage improvements, including detention facilities.

5.

Presents project concepts and plans.

6.

Identifies the area where various types of detention facilities and techniques are planned and establishes for each area the detention criteria.

B.

Restricting or prohibiting uses which are dangerous to health, safety and property due to flood, erosion or sedimentation or which result in damaging increases in erosion or in flood heights or velocities.

C.

Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction.

D.

Controlling the alteration of natural flood plains, stream channels and natural protective barriers, which help accommodate or channel flood waters and sediment; and where development will alter the surface of the ground so as to increase the rate and volume of runoff, constructing storm runoff detention facilities in accordance with the master plan of drainage.

E.

Controlling filling, grading and other development which may increase flood damage.

F.

Regulating the construction of flood barriers which will divert flood waters and sediment or which may increase flood hazards in other areas, including regulating the design of highways so as to prevent the collection and concentration of flow on the alluvial cone.

G.

Maintaining the natural radial flow pattern for storm runoff on the alluvial cone, thus avoiding the collection and concentration of flood and sediment flows toward the central part of the city.

(Ord. 841, 2-23-1988, eff. 3-23-1988)

For the purposes of applying the requirements of this chapter, the following terms are defined:

All the definitions as set forth in section 11-1-3 of this title.

ALLUVIAL CONE: That land form characteristic of desert foothills areas formed by the gradual deposition of rock, sand and soil washed out of the mountains by flood runoff. Alluvial cones are characterized by the absence of a well defined watercourse; instead, the flood runoff tends to migrate from place to place across the cone as ongoing erosion and deposition of streamborne sediments continually alter the flow path.

AREA OF SHALLOW FLOODING: A designated AO or VO zone on the flood insurance rate map (FIRM). The base flood depths range from one foot (1') to three feet (3'), a clearly defined channel does not exist, the path of flooding is unpredictable and indeterminate, and velocity flow may be evident.

AREA OF SPECIAL FLOOD HAZARD: The land in the flood plain subject to a one percent (1%) or greater chance of flooding in any given year. This area is designated as zones A, AO, AH, A1-30, VO and V1-30 on the FIRM.

BASE FLOOD: The flood having a one percent (1%) chance of being equalled or exceeded in any given year.

BASE FLOOD ELEVATION: The water surface elevation resulting from the base flood plus an allowance for future development and sediment.

DEVELOPMENT: Any manmade change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations.

ELEVATION: The elevation above mean sea level based on the city of Boulder City bench circuit provided by the city department of public works, engineering division.

FEMA: Federal emergency management agency.

FHBM: Flood hazard boundary map.

FIA: Federal insurance administration.

FIRM: See definition for Flood Insurance Rate Map.

FLOOD BOUNDARY FLOODWAY MAP: The official map on which the federal insurance administration has delineated both the areas of flood hazard and the floodway.

FLOOD INSURANCE RATE MAP: The official map on which the federal insurance administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the city.

FLOOD INSURANCE STUDY: The official report provided by the federal insurance administration that includes flood water surface profiles, the flood boundary floodway map and the water surface elevation of the base flood.

FLOOD OR FLOODING: A general and temporary condition of partial or complete inundation of normally dry land areas caused by the unusual and rapid accumulation of runoff of surface waters and sediment from any source.

FLOODWAY: The channel of a watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot (1'). The floodway is delineated on the flood boundary floodway map.

HABITABLE FLOOR: Any floor usable for living purposes, which includes working, sleeping, eating, cooking or recreation, or a combination thereof. A floor used only for storage purposes is not a "habitable floor".

NFIP: National flood insurance program.

NEW CONSTRUCTION: Structures for which the "start of construction" commenced on or after the effective date of this chapter.

PUD: Planned unit developments, as regulated by chapter 26 of this title.

SEDIMENT: Rock, sand, mud, vegetation and other material produced by erosion, carried and deposited by flood waters.

START OF CONSTRUCTION: The first work which changes the surface of the land with regard to drainage characteristics. Such work includes excavation, fill and grading.

SUBSTANTIAL IMPROVEMENT:

A.

Any repair, reconstruction or improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either:

1.

Before the improvement or repair is started; or

2.

If the structure has been damaged and is being restored, before the damage occurred. For the purposes of this definition, "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.

B.

The term does not, however, include either:

1.

Any project for improvement of a structure to comply with existing state or local health, sanitary or safety code specifications which are solely necessary to assure safe living conditions; or

2.

Any alteration of a structure listed on the national register of historic places or a state inventory of historic places.

(Ord. 841, 2-23-1988, eff. 3-23-1988; amd. Ord. 1162, 11-27-2001, eff. 12-19-2001)

A.

Lands To Which This Chapter Applies. This chapter shall apply to all areas within the city.

B.

Basis For Establishing The Areas Of Special Flood Hazard And Other Areas Covered By This Chapter.

1.

The areas of special flood hazard are those areas identified by the federal insurance administration in a scientific and engineering report entitled "The Flood Insurance Study for the City of Boulder City, Nevada", dated August 16, 1995, and all subsequent revisions, with an accompanying flood insurance rate map, which are hereby adopted by reference and declared to be a part of this chapter. The flood insurance study and the rate map are on file at the office of the city engineer, 401 California Avenue, Boulder City, Nevada.

2.

The other areas covered by this chapter are those subject to flood or sediment hazard and those which produce flood or sediment runoff as identified by the city engineer and/or by the master plan of drainage.

C.

Compliance. No structure shall be constructed, located, extended, converted or altered in the city without full compliance with the requirements of this chapter and other applicable provisions of this code.

D.

Abrogation And Greater Restrictions. This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants or deed restrictions. However, where this chapter and any other provisions of this code, another easement, covenant or deed restriction, conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

E.

Interpretation. In the interpretation and application of this chapter, all provisions shall be:

1.

Considered as minimum requirements.

2.

Liberally constructed in favor of the purposes of this chapter.

3.

Deemed neither to limit nor repeal any other powers granted under this code or state law.

F.

Limitation. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes.

This chapter does not imply that any land within the city will be free from flooding or flood damages. This chapter shall not create liability on the part of the city, any officer or employee thereof, or the federal insurance administration, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.

G.

Effective Date For Items Related To The Master Plan Of Drainage And The Drainage Manual. Those provisions of this chapter relating to the master plan of drainage and the drainage manual shall become effective upon the date of adoption by the city council of the master plan of drainage and the drainage manual, respectively, following public hearings as required by Nevada Revised Statutes 278.

(Ord. 1162, 11-27-2001, eff. 12-19-2001)

A.

General Standards. In all areas of flood hazards where base flood elevation data has been provided by the flood insurance study (subsection 11-40-6B of this chapter) or from other sources as provided by subsection 11-40-8C9 of this chapter, the following provisions are required:

1.

Anchoring.

a.

All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.

b.

All mobile homes shall be anchored to resist flotation, collapse or lateral movement by providing over the top and frame ties to ground anchors. Specific requirements shall be that:

(1)

Over the top ties be provided at each of the four (4) corners of the mobile home, with two (2) additional ties per side at intermediate locations, with mobile homes less than fifty feet (50') long requiring one additional tie per side.

(2)

Frame ties be provided at each corner of the home with five (5) additional ties per side at intermediate points, with mobile homes less than fifty feet (50') long requiring four (4) additional ties per side.

(3)

All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds.

(4)

Any additions to the mobile home be similarly anchored.

2.

Construction Materials And Methods.

a.

All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

b.

All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

c.

All future drains shall be designed using the nested three (3) hour storm pattern with a depth of 3.10 inches and a peak one hour intensity of 2.73 inches. Runoff factor and storm water design shall be based on volume 4 of the Clark County flood control master plan which is the flood control design manual.

3.

Utilities.

a.

All new and replacement water supply and sanitary sewage systems shall be designed to minimize, prohibit or eliminate infiltration of flood waters into the system and discharge from systems into flood waters.

b.

On site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

4.

Subdivision Proposals.

a.

This subsection shall apply to all subdivisions, parcel maps and planned unit developments (PUDs). For the purpose of this subsection, the term "subdivision" embraces subdivisions, parcel maps and PUDs as defined in Nevada Revised Statutes 278 and 278(A).

b.

All subdivision proposals shall be consistent with the need to minimize flood damage.

c.

All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.

d.

All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage in a manner which does not increase flood hazards to adjoining or downstream properties.

e.

Base flood elevation data shall be provided for all subdivision proposals and other proposed development.

f.

No subdivision lots shall be approved within regulatory floodways. If flood control facilities are proposed that result in an adjustment to a floodway and these are approved by FIA, the city may approve the subdivision.

g.

Subdivision lots having areas of one-fourth (¼) acre or less shall be elevated above the base flood level. Subdivision lots having areas greater than one-fourth (¼) acre shall have a building pad of at least four thousand (4,000) square feet elevated above the base flood level.

h.

Subdivision drainage must be designed to preserve the drainage area boundaries in accordance with the master plan of drainage.

i.

Each subdivision must be protected against off site flood waters and sediment in a manner which does not significantly increase flood levels, deflect flows or cause erosion or sedimentation problems.

5.

Storage Of Material And Equipment.

a.

The storage or processing of materials that are in time of flooding buoyant, flammable, explosive or could be injurious to human, animal or plant life is prohibited.

b.

Storage of other material or equipment may be allowed if not subject to major damage by floods and firmly anchored to prevent flotation or if readily removable from the area within the time available after flood warning.

6.

Natural Watercourses. Alteration or obstruction of significant natural watercourses without the written permission of the city engineer is prohibited.

B.

Specific Standards. In all areas of flood hazards where base flood elevation data has been provided by the flood insurance study (subsection 11-40-6B of this chapter) or from other sources as provided by subsection 11-40-8C9 of this chapter, the following provisions are required:

1.

Residential Construction. New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above base flood elevation, plus an allowance for sediment and future development.

2.

Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to the level of the base flood elevation, plus an allowance for sediment and for future development; or, together with attendant utility and sanitary facilities, shall:

a.

Be floodproofed so that below the base flood level, plus an allowance for sediment and for future development, the structure is watertight with walls substantially impermeable to the passage of water and protected from erosion;

b.

Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

c.

Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifications shall be provided to the building official as set forth in subsection 11-40-8D3d of this chapter.

3.

Mobile Homes.

a.

Mobile homes shall be anchored in accordance with subsection A1b of this section.

b.

For new mobile home parks and mobile home subdivisions; for expansions of existing mobile home parks and mobile home subdivisions where the repair, reconstruction or improvement of the streets, utilities and pads equals or exceeds fifty percent (50%) of the value of the streets, utilities and pads before the repair, reconstruction or improvement has commenced; and for mobile homes not placed in a mobile home park or mobile home subdivision, require that:

(1)

Lots are elevated on compacted fill above the base flood level and protected from erosion.

(2)

Adequate surface drainage and access for a hauler are provided.

c.

No mobile home shall be placed in a floodway. If flood control facilities are proposed that result in an adjustment to the floodway and the adjustment is approved by the FIA, the city may approve the placement of the mobile home.

4.

Development Over Two Acres. Any development larger than two (2) acres which is not a subdivision shall be required to meet the requirements for subdivisions if the city engineer determines that the flood hazard and the implementation of the master plan of drainage so require.

C.

Floodways. Located within areas of special flood hazard established in subsection 11-40-6B of this chapter are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry sediment, potential projectiles and erosion potential, the following provisions apply:

1.

Prohibit encroachments, including fill, new construction, substantial improvements and other development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge, any deflection of flow or any erosion or sediment hazard.

2.

If subsection C1 of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of subsections A and B of this section.

D.

Shallow Flooding. Located within the areas of special flood hazard established in subsection 11-40-6B of this chapter are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one foot (1') to three feet (3') where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions apply:

1.

All new construction and substantial improvements of nonresidential structures have the lowest floor, including basement, elevated above the crown of the nearest street to or above the depth number specified on the city's FIRM with an allowance for sediment and future development.

2.

All new construction and substantial improvements of nonresidential structures shall be protected against erosion and sediment; and shall:

a.

Have the lowest floor, including basement, elevated above the crown of the nearest street to or above the depth number specified on the FIRM, whichever is higher, with an allowance for sediment and future development; or

b.

Together with attendant utility and sanitary facilities be completely floodproofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.

(Ord. 1162, 11-27-2001, eff. 12-19-2001)

A.

Permit Required. It shall be unlawful for any person to begin any construction or development on any land within the city without first obtaining the appropriate building or zoning permit from the building official. Application for permit shall be made on forms furnished by the building official and may include, but not be limited to, plans in duplicate drawn to scale showing the nature, location, dimensions and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities; debris control structures; and the location of the foregoing, all in accordance with title 5 of this code and this title.

Specifically, the following information is required:

1.

Elevation of the lowest floor (including basement) of all structures located in any zone A on the FHBM.

2.

Elevation to which any structure has been floodproofed.

3.

Certification by a registered professional engineer that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in subsection 11-40-7B2 of this chapter.

4.

Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.

B.

Designation Of Public Works Director. The public works director is hereby appointed to administer and implement this chapter in the manner described below.

C.

Duties And Responsibilities Of Public Works Director. Duties of the public works director shall include, but are not limited to:

1.

Comprehensive Plan. Periodically review the comprehensive plan and develop and present to the planning commission and to the city council for adoption proposed revision of the comprehensive plan embodying the policies of flood damage prevention contained in this chapter and any amendments thereto.

2.

Master Plan Of Drainage. With the advice and assistance of an advisory committee consisting of representatives of interested groups and other interested persons, prepare and present to the planning commission and to the city council for adoption of a master plan of drainage for the city in accordance with the procedures set forth in Nevada Revised Statutes 278, including the holding of public hearings before both boards. Periodically review this master plan and make recommendations to the planning commission and the city council to assure its currency. The master plan of drainage and the periodic reviews shall include the following:

a.

A statement of the nature of the current flood problems facing the city, the alternatives available for addressing the problems, the adopted policy and goals of the city on flood damage prevention and progress made toward implementation of the master plan.

b.

A determination of all drainage areas tributary to the city and a definition of drainage subareas in sufficient detail to provide guidance for public and private development projects. This subarea definition will serve to maintain the radial flow paths on the alluvial cones.

c.

Future development assumptions.

d.

Level of protection in terms of flood frequency for design of projects and protection of improvements.

e.

Design flood discharges for the drainage subareas.

f.

Definition of the area in which detention of storm runoff is planned.

g.

Definition of the amount of detention required in terms of inches of rainfall over the drainage area.

h.

Project concepts and plans for master plan of drainage projects, with alignments, size, grade, and right of way requirements.

i.

Criteria and standards for developments, highway drainage and flood control projects, including detention facilities.

j.

Floodways and mandatory flood insurance areas.

3.

Drainage Manual. With the advice and assistance of an advisory committee consisting of representatives of interested groups and other interested persons, develop and present to the planning commission and to the city council for adoption a drainage manual for the city in accordance with the procedures set forth in Nevada Revised Statutes 278, including the holding of public hearings before both boards, and implement and maintain for city staff, developer and highway design use the drainage manual containing as a minimum:

a.

A statement of the flooding problem, its potential for increase and the policy and goals of the city.

b.

Description of the detention concept and the preservation of radial flow paths.

c.

Hydrologic criteria.

d.

Procedures for drainage, detention, sediment control, floodproofing, subdivision design and road design.

e.

Drainage area boundary map, soil type map, soil runoff characteristics, rainfall mass curves, sediment criteria, detention basin standards, floodproofing standards and road design standards.

f.

Standard drainage structures.

4.

Zone Change Requests. Review all zone change requests from the standpoint of drainage and file a written report with the planning commission on the flood hazard to the parcel, the potential for increasing the flood hazard by development of the parcel, the presence of any master plan of drainage facilities affecting the parcel and the potential need for detention and/or other drainage improvements. The purpose of this report is to bring to light, for the benefit of the developer and the planning commission, at the earliest possible stage of planning, the nature and extent of flood problems and the mitigation that will be required.

5.

Subdivision, Parcel Maps, Planned Unit Development. Develop, implement and maintain drainage procedures for subdivision, minor land division and planned unit development with the objectives of:

a.

Requiring the identification and resolution of drainage problems at an early stage of planning, while other factors are still sufficiently flexible to accommodate adjustment.

b.

Ensuring the adequacy and currency of the procedures in implementing the master plan of drainage and the provisions of this chapter.

6.

Drainage Deficiency Inventory. As part of the master plan of drainage, develop and present to the city council annually, a report on drainage deficiencies, containing an updated inventory of drainage deficiencies, with their relative priority and estimated cost, and a report on progress made on correcting deficiencies since the last report.

7.

Flood Insurance Information. Initiate and maintain a public information program to achieve voluntary flood insurance coverage for all structures in the city subject to flood and/or sediment damage.

8.

Development Review.

a.

Review all applications for subdivision, planned unit development, and parcel maps to determine if the proposed development adversely affects the flood and sediment carrying capacity of the area of special flood hazard. For purposes of this chapter, "adversely affects" means that the cumulative effect of the proposed development when combined with all other existing and anticipated development will not increase the water surface elevation of the base flood more than one foot (1').

b.

Review each subdivision and PUD proposal for overflow, erosion and deposition of sediment and certify prior to approval that all flood hazards have been mitigated in accordance with the master plan of drainage, the drainage manual and the requirements of this chapter. As a minimum, this review shall consider the following:

(1)

The drainage area tributary to the proposed development.

(2)

The 10- and 100-year flood discharges with an allowance for sediment and future development.

(3)

The flow pattern prior to the proposed development.

(4)

The depth and velocity of flow across or adjacent to the parcel.

(5)

The proposed measures for protecting the development from flood and sediment.

(6)

The effect of the development on the existing flow pattern and the resulting effect on adjacent and downstream properties.

No development shall be approved until it is demonstrated that the development is adequately protected from flood and sediment and that the development does not increase the hazard to adjacent properties by increasing flood levels, deflecting flows or causing erosion or sedimentation problems.

9.

Use Of Other Base Flood Data. In addition to the base flood elevation data provided in the flood insurance study, the public works director may obtain, review and reasonably utilize any other base flood elevation data available from a federal, state or other source, in order to administer subsections 11-40-7B1 and B2 of this chapter.

10.

Alteration Of Watercourses.

a.

Notify adjacent communities and the Nevada department of conservation and natural resources prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the FIA.

b.

Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood carrying capacity is not diminished.

c.

Regulate the alteration of any watercourse which will increase flood heights, deflect flows or cause erosion or sedimentation hazards.

11.

Interpretation Of FIRM Boundaries. Make interpretations, where needed, as to the exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in subsection E of this section.

D.

Duties And Responsibilities Of Building Official. Duties of the building official shall include, but are not limited to:

1.

Building Permit Drainage Procedures. Develop, implement and maintain permit procedures for building permits with the objectives of:

a.

Requiring the identification and resolution of drainage problems at an early stage of planning, while other factors are still sufficiently flexible to accommodate adjustment.

b.

Ensuring the adequacy and currency of the procedures in implementing the master plan of drainage and the provisions of this chapter.

2.

Permit Review. Review all applications for permits to determine that the requirements of this chapter have been satisfied and that the structure would be reasonably safe from flooding.

3.

Information To Be Obtained And Maintained.

a.

Obtain and record the actual elevation (in relation to mean sea level) of the lowest floor (including basement) of all structures new or substantially improved within any zone A as shown on the FHBM after the FIRM dated August 16, 1995, and all subsequent revisions following the date of the map.

b.

For all new or substantially improved floodproofed structures:

(1)

Record the actual elevation of as built structures (in relation to mean sea level).

(2)

Maintain the floodproofing certifications required in subsection A3 of this section.

c.

Maintain for public inspection all records pertaining to the provisions of this chapter.

d.

Certification of actual elevation will be the responsibility of the developer and must be furnished by a land surveyor registered in the state.

E.

Administrative Appeals And Variances.

1.

Appeals.

a.

The planning commission shall hear and decide appeals when it is alleged there is an error in any decision, determination or interpretation by the public works director regarding the requirements of this chapter.

b.

Such appeals shall be made in accordance with the provisions of Nevada Revised Statutes 278.310.

c.

Prior to the hearing on the appeal, the author of the decision being appealed shall file a report with the planning commission supporting his decision. Such report shall, as near as practicable, contain the information required in subsection E2c of this section.

2.

Variances.

a.

The planning commission shall hear and decide requests for variances from the requirements of this chapter in the manner and in accordance with the procedures set forth in chapter 32 of this title with the exception that the planning commission shall consider, instead of the conditions enumerated in section 11-32-4 of this title, those conditions required in subsection E4 of this section.

b.

Any person aggrieved by the decision of the planning commission on a variance application may appeal such decision to the city council in the manner and in accordance with the procedures set forth in chapter 34 of this title.

c.

Prior to the public hearing on the variance before the planning commission, the public works director shall file a report with the planning commission on the application for a variance, which shall contain the following information at a minimum:

(1)

Location of the parcel;

(2)

The tributary drainage area;

(3)

The 10- and 100-year flood discharge, with an allowance for sediment and future development;

(4)

The depth and velocity of flow across or adjacent to the parcel;

(5)

The requirement from which a variance is requested;

(6)

Engineering considerations underlying the requirement;

(7)

Possible alternatives to the requirement;

(8)

Mitigating circumstances, if any;

(9)

Recommended action.

d.

In passing upon applications for variances, the planning commission shall consider the report provided for in subsection E2c of this section, all technical evaluations, all relevant factors and standards specified in other sections of this title.

e.

Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (½) acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items in subsection E2c of this section have been fully considered. As the lot size increases beyond the one-half (½) acre, the technical justification required for issuing the variance increases.

f.

The planning commission may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.

3.

Records. The public works director shall compile and maintain a complete record of all appeals and variances filed with the planning commission, report any variances to the FIA upon request and shall include statements documenting the findings required for variances under subsection E4d of this section.

4.

Condition For Variances.

a.

Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places without regard to the procedures set forth in the remainder of this section.

b.

Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.

c.

Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

d.

Variances shall only be issued upon:

(1)

A showing of good and sufficient cause;

(2)

A determination that failure to grant the variance would result in exceptional hardship to the applicant; and

(3)

A determination that the granting of a variance will not result in a significant increase in flood heights, threats to public safety, extraordinary public expense, create nuisances or conflict with existing local laws or ordinances.

e.

Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation, as required by the FIA.

5.

Technical Committee. The public works director shall appoint a drainage technical committee consisting of three (3) members chosen from the general public in the city who have technical knowledge and experience in civil engineering and/or flood control engineering and who would be qualified to assist in the appeal or variance review process set forth above on an as needed basis. The applicant at his or her option may elect at the time of the filing of an appeal or an application for a variance to have the drainage technical committee review said application prior to the hearing and make a recommendation thereon to the planning commission. The public works director may charge the applicant an administrative fee to defray the costs of the review and preparation of a report.

The initial members of the drainage technical committee shall be appointed for one, two (2) and three (3) year terms and all subsequent appointments shall be for two (2) years. All vacancies occurring during a term of office shall be filled to the end of the term. Members may be removed by the public works director or the city manager for cause.

(Ord. 1350, 1-22-2008)

The uniform regulations for the control of drainage, adopted by the Clark County regional flood control district, and as may hereafter be amended, are hereby incorporated by reference and made an integral part of this chapter. In the event the requirements of the Clark County flood control district, as they now exist or may hereafter be amended, are in conflict with the provisions of this chapter, such specific requirements which are more restrictive shall apply.

(Ord. 851, 10-25-1988, eff. 11-16-1988)