KING COUNTY

RON SIMS, KING COUNTY EXECUTIVE

DEPARTMENT OF NATURAL RESOURCES

Pam Bissonnette, Director

WATER AND LAND RESOURCES DIVISION

Nancy Hansen, Manager

Debbie Arima, Assistant Manager

Curt Crawford, Manager, Local Drainage Services Unit

CONTRIBUTING STAFF

Doug Rice, Writing/Illustrations/Photography

Betty Hageman Graphic Design

Louise Kulzer, Water Quality Specialist

SPECIAL THANKS

Peggy Gaynor, Landscape Architect

Sally Schauman, Landscape Architect/Educator

For Information Call or Write:Doug Rice, Landscape Architect or Louise Kulzer, Water Quality SpecialistKing County Water and Land Resources Division700 Fifth Avenue, Suite 2200Seattle, WA 98104(206) 296-6519

September 1998Funded by King County Water and Land Resources Division

THE

INTEGRATED

POND

Cover photo:

Ballinger Commons

Water Quality Pond

PRINTED ONRECYCLED

PAPER

THIS INFORMATION ISAVAILABLE ON REQUEST INACCESSIBLE FORMATS FOR

PEOPLE WITH DISABILITIES BY

CALLING (206) 296-8360

TABLE OF CONTENTS

PART I

INTRODUCTION 1

So why are ponds ugly? 2

A change of direction 2

LOOKING IN NEW

DIRECTIONS 3

The role of ponds 3

Beyond the singlefunction pond 3

The challengefrom engineering 4

Ponds with value-added amenities 5

Economic benefits ofwater quality wetponds 6

FOCUSING ON

ENHANCEMENT 8

Techniques that work 8

– Screening 8

– Visual integration 11

– Functionalintegration 14

– Designing formaintenance 15

A QUALITY FUTURE 17

Unresolved issues 17

Quality environments 17

PART II

CASE STUDIES 19

A. Evergreen Vale 19

B. Ballinger Commons 19

C. Juanita Springs andSpringwood 20

D. Providence Point 20

E. Two Habitat Ponds 21

F. MeadowbrookReflective Refugeand SedimentationPond 22

G. Waterworks Gardens 23

H. Audubon Park 24

I. Issaquah Highlands 25

REFERENCES 26

STORMWATER IS NOT

WASTEWATER,

IT IS A RESOURCE –

AS POTENTIAL GROUND

WATER, AS UNPOLLUTED

WATER, AS HABITAT,

AS AMENITY.

“WHEN ALL ELSE IS EQUAL,

THE PRICE OF A HOME

LOCATED WITHIN 300 FEET

FROM A BODY OF WATER

INCREASES BY UP TO

27.8 PERCENT”

1991 AMERICAN HOUSING SURVEY

PART IINTRODUCTION

After nearly two decades ofrequiring, designing, reviewingand living with stormwaterstorage ponds in the PacificNorthwest, the King CountyWater and Land ResourcesDivision (formerly KingCounty Surface Water Manage-ment) is confronting pondshortcomings – technical,esthetic and social – andpursuing their potential forimprovement. Several genera-tions of these facilities areproviding information withwhich to improve design,function and place in ourcommunities. There is nocomprehensive solution to thevarious impacts these necessaryfacilities have on our communi-ties. There are, however, newand coming regulatoryflexibilities, clear and continu-ing demands for protecting andenhancing quality of life, agrowing recognition thatthrough public/private collabo-ration, improvements are

possible, affordable and benefi-cial to all.

There is now ample evidence,both locally and nationally, thatwell designed ponds withattractive landscape buffers,and/or passive recreationalfeatures, can become major siteamenities and contribute bothadded value and quality openspace. Studies by the UrbanLand Institute show that“quality landscape designand amenities can contrib-ute substantially to both thereal (...financial...) andperceived (...quality of life)value of a real estatedevelopment project.” 1

Their evidence shows thatquality landscaping andamenities:

◗ “Can translate into increasedfinancial returns for aproject’s developers.

◗ Give developers a competi-tive edge and increase thepace of a project’s absorp-tion.

◗ Are a key factor in establish-ing an image, identity, andsense of community fordevelopment projects.

◗ Include passive amenitiesthat are often more valuedthan provisions for activerecreation.

◗ Contribute substantially tothe perception of security,privacy, and place.” 2

This water quality pond at Winterwood in Covington doubles aswaterfront and parkland.

1

So Why are Ponds Ugly?

Though ponds provideimportant safeguards againstflooding, erosion and waterresource degradation they canalso be unattractive, expensive,mono-functional, and hard tomaintain. County pond designstandards tend to be prescrip-tive. Few guidelines exist fordirecting designers and buildersto appropriate and integrativedesign solutions. Developers seethe pond as a cost burden andavoid the expense of mitigatingpond appearance becausedesign variances can be expen-sive and time consuming.

Contractors bid and buildprojects for maximum return oftheir time and labor. Trees andslope variations in small scaleenvironments, including ponds,are impediments that aretypically removed to achievethe desired profit or break-evencontract. Subsequent countymaintenance is necessarilyminimal. Too often, pondsresemble gravel pits, muddyholes in the ground, or vacantlots. Frequently, those who livenearby perceive these ponds as“the ugly thing the governmentmade us build.” Houses builtnext to these facilities can be

less desirable to buy. Develop-ers, in an effort to maximizebuildable land, often includeno separation or transitionspace around ponds and optinstead for smaller but steep,unattractive ponds requiringsafety fencing.

Because ponds are rarelygiven a use outside theirprime function they oftenlack any visual or actualconnections to the neigh-borhoods they serve. Butthere can be significant advan-tages to upgrading the visualappearance and multi-function-ality of ponds. Ponds withperimeter plantings resemblingthe surrounding neighborhoodcontribute attractive open spacerather than detractive emptyspace. Large ponds with gentleslopes can be made into viable

park and passive or activerecreational space. Waterquality ponds can be fit withfountains or be made toresemble a wetland.

A Change of Direction

The Water and Land Re-sources (WLR) Division wouldlike to encourage all partici-pants involved in the complexprocess of pond regulation,design, financing, construction,review and maintenance toexplore the challenges andopportunities that pondspresent. We are already in theprocess of updating regulatorystandards to allow for greaterflexibility. Other efforts havebeen made by the County toenhance ponds within existingcommunities. This booklet is

This is typical of hundreds of similar detention ponds – functionalbut ugly.

This water quality pond at Audubon Park exhibits the best incurrent water quality pond design – fountains, landscaping, placesfor people.

2

meant to open the door tofurther discussion and change.It details the very real problemsinherent in pond function,engineering, maintenance, cost,and size. It also suggests oppor-tunities for improvement inthese areas and offers sugges-tions which focus on enhance-ment techniques. In the decadeahead, we are looking forwardto future improvements in bothpond design and usefulnessfacilitated by more flexibleregulations and a sharedapproach to their care andmanagement.

wise, part of the projectrecreation requirement may beapplied to the pond site if eitheractive or passive opportunitiesnecessarily bare appearance.

3

LOOKING IN NEWDIRECTIONS

The Role of Ponds

The typical detention pond isusually dry, holding water afterlarge storms and then allowingit to exit at a slow rate. Theseponds are standard for residen-tial developments where theamount of impervious surfaceis high, i.e. many roofs, streetsand driveways. Water qualityponds generally holdstormwater all the time. Thewater is purified by settling andby biological processes. Theyare standard for larger develop-ments. Some ponds combinethe functions of detention andwater quality ponds. To befunctional, both types of pondmust provide sufficient waterstorage capacity as well as accessfor maintenance. These andother basic functional andlandscape requirements areoutlined in the King CountySurface Water Design Manual.However, the manual primarilyaddresses stormwater and can

only minimally treat landscapeissues.

Beyond the Single FunctionPond

As long as the primarystormwater managementfunction is retained, and aspecial use permit is approved,ponds can be put to uses that

add to the value of surroundingproperties. With suburbandensities increasing, we can illafford to overlook potentiallyvaluable recreational or openspace. Instead of being seen asugly, left-over space, it canbecome a recreational orhabitat amenity, relating the

An older but well integrated water quality pond at Springwoodenhances the quality of life for residents.

A basketball court was installed in this detention pond.

pond to its neighborhood in amulti-functional manner.

A few ponds have alreadybeen used for additionalpurposes and these can pointthe way toward a more integra-tive approach to pond design inthe future. For example, someneighborhoods have sportcourts installed on the bottomlevel of dry detention ponds.Other neighborhoods havestrolling, running and interpre-tive trails around their waterquality ponds – some of whichare also natural wetlands orbegin to resemble wetlands. Awider buffer area between pondand residences can serve aspicnic and children’s play areas.Some developers have used thepond as part of the subdivisionentry, installing attractivesignage and landscaping theedges. In these cases thehomeowner’s association mustprovide enhanced maintenance.

Some other possible uses forponds might include:

◗ Living laboratory – whereoutdoor classrooms couldmeet for ecological study ofwet landscape systems orwhere students could con-duct school projects.

◗ Terraced Court – straightsided walls built of rockgabions or retaining systemblocks and terraced to holdplantings or patios. Thisfeature would never needmowing and could be usedfor community gatherings,activities or events.

◗ Environmental art feature –i.e. earth works, sculptures,etc.

◗ Community garden featureor pea patch

◗ Decorative water feature

◗ Play courts

The Challenge FromEngineering

For 15 years, engineers at theWLR Division have beenimproving regulations aroundthe functional aspects of ponds– their construction,holding capacities,shapes, sizes and costs.Changes to the DesignManual will continue tobe considered in futureupdates. New changesto the Design Manualinvolving landscapinginclude:

◗ The number of holding cellsin ponds has been reduced – asingle cell in detention pondsand only two cells in waterquality ponds.

◗ A better design for “com-bined” ponds that have both apermanent stormwater pool aswell as additional room forpeak flow detention on top.These ponds have fewerberms, are deeper (permanentpool is an average of four feetor more), and have morewater surface than the olddesigns. They are better atstormwater treatment, butthey also improve esthetic andlandscape possibilities (e.g.the use of fountains).

This community used a large underground tank to detainstormwater over which an entire neighborhood playground andpicnic area was built.

4

Irregular edgesenhancenaturalisticappearances.

E X I S T I N G P L A N T I N G

Straight planting edge

P O N D

Irregular planting edge

P O N D

THIS

NOT THIS

◗ If a water quality pond isbuilt four times longer thanit is wide, only a single cell isnecessary. The resulting lookof the pond is more linearand less box-like. A curvinglinearity can integrate betterwith natural topographiesand greenbelts.

◗ Access ramps need only beprovided to the first cell of atwo cell pond. Moreover,ramps can use gravel or a“Grasscrete” like productinstead of asphalt.

◗ Perimeter roads are no longerrequired. When re-landscap-ing an older pond (pre-1998), these portions ofroads may sometimes beused as planting areas.

◗ Fences required for steep sideslopes only need to be abovethe slope area, not necessarilyaround the whole pond.

Alternatives to chainlinkfence are also allowed ifprivately maintained. Woodfences, recycled plasticfencing, vertical bar fencesand use of thorny shrubs likeholly, rosa rugosa andbarberry are also options.

◗ Erosion control options inaddition to hydroseeding arenow allowed. Four to sixinches of “hog fuel” woodchips held in place with jutenetting makes it easier toinstall non-grass plantings.

◗ Very basic landscapingguidance for “natural look-ing” ponds is provided, andsuch ponds are allowed inopen space tracts, at least forsome programs (like theFour-to-One zoning pro-gram in case study I).

Volume-for-volume,straight slopes fill fastand infiltrate slowly.Slope and pond serve noother purpose.

Flatter slopes fill slowly and infiltratemore rapidly, allowing slopes to be usedfor other purposes such as wetlandhabitat or recreation.

Hopefully, these improve-ments and others will add moreflexibility to design options.Remember, that while theDesign Manual does notaddress the multi-purpose useof ponds, it does not prohibitsuch use.

Ponds with Value AddedAmenities

Many ponds lack any visualor biotic relationship to theirsurroundings. Many have beeninvaded by weeds and arelittered with rocks. Theseponds do not work well as openspace and are hardly neighbor-hood amenities. In the past,developers and engineers haveoften dealt with the problemsof pond size and cost by

squeezing them into steep-sidedrectangular pits surrounded bythe requisite cyclone fence.These truly ugly ponds canimpact the enjoyability, valuesand salability of the propertiessurrounding them, thus costingthe developer and subsequentbuyers even more.

There has been an interest onthe part of some developers toincorporate well designedamenities into the pond design.Case studies included in Part IIof this booklet document someof their successes. BesidesDesign Manual changes, one ofthe ways the County is begin-ning to help is by allowing 50percent of the landscaperequirement for a developmentto be applied to part of the

A park with tennis court was built around this water quality pondat Winterwood.

5

Views of water – even stormwater in this case – can add real valueto the sale of a house.

Upper levels of stormwater detention are devoted to infrequent flood flows. These flows could bewidely spread into a grassy “green” for use as a golf course or park-like recreation area. Manydetention ponds are wet only a few times a year during heavy storm events and may infiltratequickly.

6

Ponds can be designedto be linear orstreamlike. Thesinuosity works well innarrow spaces. Linkedbiofiltration swales,wet ponds anddetention ponds canresemble a naturalsystem when planted.

pond if the surrounding areais landscaped and functions asan amenity to the project.Likewise, part of the projectrecreation requirement may beapplied to the pond site ifeither active or passive opportu-nities are provided within oradjacent to the pond site.

The ideal pond might be avalley-like open space sur-rounded by an attractive

landscape (including paths,viewpoints, sitting or playareas) which may connect to alarger neighborhood trailsystem or green belt (see casestudies). This arrangementcould be at the entrance oredge, or wind centrally throughthe development with natural,undulating contours. If thepond is graded and blendedwith the topography of the site,

and fences are not visualimpediments, then the openspace is perceived as part of thesurrounding lots – whichappear larger and more valu-able. In dry detention ponds,sport courts may be formed inthe bottoms. Wet ponds couldincorporate a fountain or re-circulating waterfall feature.Native plantings could encour-age wildlife to return to dis-

turbed areas (backyard birdwatching is the fastest growingsport in the U.S.). Maintenanceof the area by the communitycould extend into the pond,creating a weed free, park-likeenvironment. This multi-functional pond, adopted byneighbors invested in theirquality of life, can be a workingmodel for designers, developers,communities and county staff.

Economic Benefits of WaterQuality Wet Ponds

Even though stormwatermanagement costs money,properly designed runoffsystems can provide economicbenefits that counterbalance oreven outweigh those costs. Thepractice of siting developmentsaround man-made ponds,

The ideal pond might be a valley-like open space surrounded by an attractive landscape. Thisarrangement could be at the entrance or edge, or wind centrally through the development withnatural, undulating contours.

7

lakes, or wetlands created tocontrol flooding and reduce theimpacts of urban runoff isbecoming more prevalent.Controls that are pleasing tothe eye and safe for childrencan lead to increased propertyvalues and enhance the quality

of life. Beautification of landareas adjacent to waterways anddetention ponds should beconsidered an integral part ofplanning by developers. A 1991American Housing Surveyconducted by the Departmentof Housing and Urban Devel-

opment and the Department ofCommerce concurs that “whenall else is equal, the price of ahome located within 300 feetfrom a body of water increasesby up to 27.8 percent” (Na-tional Association of Home

Builders, 1993). If located closeto the entrance and visible fromthe road, a pond could haveconsiderable curb appeal andcan repay installation coststhrough faster sales.