SENATE BILL REPORT

SB 6539

BYSenator Metcalf

Regulating water flows in natural drainages.

Senate Committee on Environment & Natural Resources

Senate Hearing Date(s):January 25, 1990

Majority Report:     Do pass.

     Signed by Senators Metcalf, Chairman; Barr, DeJarnatt, Kreidler, Patterson.

Senate Staff:Gary Wilburn (786-7453)

                January 29, 1990

AS REPORTED BY COMMITTEE ON ENVIRONMENT & NATURAL RESOURCES, JANUARY 25, 1990

BACKGROUND:

In many areas of Washington high rainfall frequently exceeds the capacity of natural watercourses to drain the resulting surface water.  Land use activities often impact natural drainage capacities, including increasing impervious surfaces which impact the volume and rate of runoff.  Modifying natural drainage systems also may impact the system's capacity to drain stormwaters.  If land development activities are not accompanied by proper use of natural drainage ways or construction of artificial drainage systems, downgradient owners may either suffer property damage or be burdened by increased cost to protect their lands from damage.

In property damage actions, Washington courts have adopted rules followed in only a minority of courts today.  This rule regards diffuse surface water as the "common enemy" which a landowner may divert from his or her lands to another's land without liability.  The upper landowner may augment the flow of natural watercourses and cast a greater volume onto the lower land, and may discharge water at a different point from its natural flow.  The upper owner may raise the land level or increase the impervious surfaces of the land without regard for the effect upon surface water flow.  The "common enemy" rule has been criticized as being unfair to downgradient landowners and lacking in clarity.

SUMMARY:

A person may not substantially increase the flow of a natural watercourse where the flow exceeds the capacity of the watercourse that existed prior to the person's action.  "Watercourse" is defined as a channel, depression or swale, that in its natural condition, acts to drain waters flowing intermittently or perennially.  The standard is not applicable to certain activities, such as irrigation, forest practices, drainage within flowage easements, or drainage in compliance with state or local permits incorporating stormwater management requirements.

State and local agencies are to incorporate the standard into any permit which provides stormwater management requirements.

Appropriation:  none

Revenue:   none

Fiscal Note:    requested January 19, 1990

Senate Committee - Testified:   Kathleen Collins, Association of Washington Cities (pro)