Newslettef of the Issa quah Alps Trails Club lUt4G COUNTY iNftLjM Use IN Library -k F6 Our Issaquah A uifer George Comstock he next time you take a walk on the Lake Tra1i with gravel, with a small city on top. The Issaquah To think of the Issaquah aquifer as a gravel filled tion Plateau, take a close look at Lake Traditin aquifer extends all across the valley floor, bounded lake is misleading in one respect, however, since it Tand see if something doesn't strike you as a little by Tiger Mountain to the east, Squak and Cougar doesn't give a feeling for the considerable movement odd. Where does this water come from. Where does Mountains to the south and west, Lake Sammamish of water through these gravel deposits. This ground- it go to? Yes, you noticed it there's no stream in ot! to the north, and southward between Squak and Ti- water moves generally northward eventually enter- out of Lake Tradition, or Round Lake either. You ger to the "Issaquah Gap", located a little north of ing Lake Sammamish. The marshy area in Lake might also notice that the lake level fluctuates quie the May Valley Road. Sammamish State Park is where the aquifer is up- dramatically from season to season, and year to yar. The Lake Tradition Plateau and Grand Ridge welling from deep gravel deposits on its way to the Take a look at any map of the area, and you will (on the north side of 1-90) are very important aqui- lake. Total water flow into the aquifer is estimated at find that the Lake Tradition Plateau, including Lake fer recharge areas. Rain water falling onto these re- 20 to 25 cubic feet per second (cfs) from all these Tradition and Round Lake, are part of the City of charge areas enters the ground directly, seeps down sources: a cube of water almost 3 feet to a side enter- Issaquah Watershed. With only the lakes in min, through the ground (actually the same gravel depos- ing the ground every second! Issaquah and the Sam- one could be forgiven for not drinking the water un- its which hold the aquifer) and eventually reaches mamish Plateau presently consume about 5 cfs and til getting to Bellevue. Fortunately, however, the aquifer under Issaquah. The WPP estimates that the remaining water discharges into Lake Sam- Issaquah has extremely good drinking water, acc9rd- it takes approximately six years for rain water falling mamish. ing to a recently published technical report entitld on Grand Ridge to reach the prcduction wells near So the next time you go to the Lake Tradition "The Lower Issaquah Valley Wellhead Protection 1-90 and Front Street, and that approximately one Plateau, remember that you are standing on top of a Plan". This report evaluates the groundwater re- half of the total water supply comes from these re- large gravel sponge that some 20,000 people rely sources which some 20,000 residents of Issaquah charge areas. Other sources of water include direct upon daily for their drinking water. And how do and the Sammamish Plateau rely upon for their recharge from the valley floor, infiltration of water Lake Tradition and Round Lake manage to stay on drinking water. How does Issaquah get excellent wa- from the east and south forks of Issaquah Creek, and top of this sponge? The answer is that the gravel de- ter from a comparatively small, heavily used piece of groundwater flowing northward from the Issaquah posits which make up most of the Lake Tradition ground with two small and dubious looking "lakes?" Gap. The importance of the Lake Tradition Plateau Plateau has mixed within it pockets of impervious In fact, Issaquah and the plateau drink grou4d_ as a recharge area explains why the City of Issaquah soils like clays and silts. Two such lenses of impervi- water which collects directly under the city itself in owns it as a watershed/conservation area, although it ous soils lie under these lakes, and under other wet- gravel deposits. This water is pumped out of the doesn't shed water, but actually absorbs it. The im- land areas scattered around the plateau, which allow ground by several city owned production wells gen- portance of Grand Ridge as an aquifer recharge area rainwater to collect rather than seeping into the erally located near the 1-90 interchange at Front is also clear. King County recently stopped an urban ground. These lakes are the merest drops of water in Street, and hundreds of private wells throughoui the development of Grand Ridge pending the results of the water supply system for the area. The Lake Tra- vicinity. Drawn from what the Wellhead Protecton the WPP, and local residents will surely draw argu- dition Plateau and Grand Ridge are quite the oppo- Plan (WPP) calls an unconfined aquifer, the water ments from the WPP to fight development on top site—they are a vital element of a complex and only under the city might be described as a lake filled of their water source. partly understood water supply system. A Tradition Plateau Becomes a NRCA Pamela Wallenstein n December 20, 1993 the Issaquah City Cun- The Washington State Legislature in 1987 The City Council felt that rzbning the area as a cil changed the zoning of the Tradition PlaFeau passed the Natural Resources Conservation Areas NRCA would be consistent with the existing O from a Public Use Zone to a Natural Resources Act to "protect outstanding examples of native eco- NRCA that surrounds the Plateau and would also Conservation Area (NRCA). This new designation systems and habitat for endangered, threatened, and be in line with the recommendations of the City's was recommended by the Land Use Planning Com- sensitive plants and animals." Currently 854 acres on Trails Plan. Had it been left a Public Use Zone, ex- mittee and the Ad Hoc Trails Committee. West Tiger Mountain have been designated as a pansion could have included, among other things, In November 1992 the City Council approed Natural Resources Conservation Area by DNR. "accessory structures such as restrooms, seating, the Issaquah Area Wildlife and Recreational Trails DNR's West Tiger Mountain Draft Management [and] scoreboards." Plan. Part of the plan included recommendations for Plan recommends expanding the current NRCA to Within a NRCA, different levels of usage are the Tradition Lake Plateau. One of these recorrL include 4,400 acres on the northern and western permitted. The West Tiger Mountain Draft Man- mendations was for the City of Issaquah to "cordi- slopes of Tiger Mountain. Because the Tradition agement Plan suggests that the immediate area sur- nate and integrate recreational usage as well as Lake Plateau is surrounded by the existing NRCA rounding Tradition and Round Lakes is the most educational usage to be consistent with the Natural and because the area around the lakes is similar to environmentally sensitive. It recommends that recre- Resources Conservation status that the Departiiient the area already classified as a NRCA, DNR includ- ational use be prohibited in these areas. Other areas of Natural Resources (DNR) has given to the stir- ed Tradition Lake Plateau in its management plan. on the Plateau could be open to Class 1 activities rounding area including the Tradition Lake Plateau." story continued on page 4 1994 Issaquah Alps 1994 Goals "State of the Union" Established. Ken Konigsmark Ken Konigsmark any significant changes, some very good, ai The City "Trails Coordinator" (Margaret Ma- n1994, IATC will focus on a set of goals estab- Msome potentially ominous, will impact the cleod) is working hard to implement the Issaquah Ilished by the Board duEing a December planning Issaquah Alps area in 1994. Following our gov Trails Plan, and serves as a key link to all the manag- meeting and at the annual meeting in January. mental custom of an annual "state of the unior ing agencies for the Alps. IATC has strong, positive These goals were proposed by the Club Advocate dress, I am providing a summary of the issues relationships with DNR, King County Parks, State (see theApparatus) responsible for each of the respec- expected in the year ahead. Parks, and the City which allows dialog on land five geographic areas and provide a foundation for The overall state of the Issaquah Alps in 1 94 is management issues. We have a strong core of volun- Club efforts this year. amazingly good. Several recent, monumental Tents teers, including several new additions, who serve the have contributed to the expansion and preserv; tion Club in many. capacities. Cougar 1.Promote/obtain approval for Cougar Moun- of this priceless area: the purchase of 1800 acr on The Cougar Mountain Wildland Park Master tain Wildland Park Master Plan. Rattlesnake Ridge by DNR and King County the Plan is nearing completion, and will provide a solid Oppose/challenge the proposed Lakemont acquisition of Phase 1, Section 9 on Squak M Lintain framework for management of this regional treasure. Boulevard extension. by State Parks; the addition of another 442 aci s to DNR continues to repair and upgrade trails and fa- Restore and preserve the Licorice Fern trail. Cougar Mountain Park by King County; the j anned cilities on Tiger Mountain, an effort much appreci- acquisition of the Tibbitts property at the Hig Point ated by the numerous visitors. Tiger na- All of the above items represent extremely posi- trailhead by the City of Issaquah; and the desi Promote public acquisition of Section 12, Lquah tive things for IATC and the Alps. Yet, all is not tion of the Tradition Plateau by the City of Is Tibbetts, and Schroeder properties.