WSP05488

• File Number: 8030
• Description: Section D General Compact Issues - US Water Resources Council
• State: CO
• Basin: Statewide
• Date: 8/1/1971
• Author: US Water Resources C
• Title: Regulation of Flood Hazard Areas to Reduce Flood Losses - Draft - Volume II Part VI - Without Appendices
• Water Supply Pro - Doc Type: Report/Study

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COASTAL, FLOOD PROBLEJ1S

10

6-133.

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a natural buffer zone between the sea and easily erodable

upland. Natural changes occur in many beachei due to winds,

storm waves, waves and currents. Commonly,beaches are eroded

by win'ter storms and repaired by sU-'mner waves and currents,

continuance of the beach depends upon a natural or artificial

supply of replenishing sands.

Sand dunes,'beaohes and other protective barriers

blunt the force of winds and waves and protect backlying

lands, yet residential, commercial and industrial develop-

ment of shoreland sites has often ignored their important

ex-os ion and flood control function.2o Dunes and beach gravels

are mined for building and highway construction purposes;

and' dunes are leveled, for real estate development: or, to p:con

. vide access cr a view of the beach,

other activities of man have added to coastal problems,

Reservoirs constructed on rivers in some instances trap the

sand and silt before it can reach the sea, This sand naturally

replenishes beaches and in its absence beaches may disappear,

Groins'have often been constructed to protect beaches in

some areas, These are walls or fences constructed across

beaches out into the ,,,ater to slow the littoral drift of

sand along a beach,21

While groins retain sand and protect

beach areas on one side of the groin, downshore areas are

sometimes deprived of natural sand supply with resulting ero-

sion and flood damage,22 Breakwaters, jetties, solid wharves,

fills, seawalls,

bulkheads and other structures placed in

watcr or beach areas may also disturb the natural regime of