The City of Mercer Island Parks and Recreation owns 301 acres of open space, most of which is forested. This includes portions of properties idetified as "parks", such as the forested areas of Island Crest Park and Mercerdale Park. The City has adopted an Open Space Vegetation Plan to manage these areas.

Park Name	Location	Total Acreage	Open Space Acreage	Map It
Clarke Beach Park	7700 E Mercer Way	9.05	7.66
Clise Park	SE 40th St & Island Crest Way	1.72	1.72
Ellis Pond	SE 47th St & 90th Ave SE	4.04	4.04
Gallagher Hill	3701 SE Gallagher Hill Rd	11.34	11.34
Groveland Park	SE 58th St & 80th Ave SE	3.07	3.07
Hollerbach Open Space	SE 45th St & 91st Ave SE	5.18	5.18
Homestead Park	82nd Ave SE & SE 40th St	11.09	3.68
Island Crest Park	5500 Island Crest Way	38.91	31.20
Luther Burbank Park	2040 84th Ave SE	54.52	27.23
Mercerdale Hillside	77th Ave SE & SE 32nd St	18.59	18.59
Mercerdale Park	77th Ave SE & SE 32nd St	12.17	6.51
N. Mercerdale Hillside	7415 SE 27th St	6.20	6.20
Parkwood Ridge Open Space	9165 Parkwood Ridge Rd	3.80	3.80
Pioneer Park	SE 68th St & Island Crest Way	118.85	118.85
Salem Woods	6300 90th Ave SE	0.35	0.35
SE 47th St Open Space	4701 E. Mercer Way	1.53	l.53
SE 53rd Open Space	9100 SE 53rd Pl	24.97	24.97
SE 80th Open Space	8599 SE 80th St	3.92	3.92
Secret Park	SE 27th St & W Mercer Way	0.86	0.86
So Mercer Playfield	SE 78th St & 84th Ave SE	17.31	1.38
Wildwood Park	7400 86th Ave SE	3.02	1.92
Upper Luther Burbank Park	84th Ave SE & SE 33rd St	18.07	18.07

Open Space Vegetation Plan

The City of Mercer Island's open space properties are losing trees and native vegetation from the rampant growth of invasive, non-native plants. This trend is expected to cause significant additional losses in the next twenty years. This will result in the decline of the benefits that open space properties currently provide to the public.

Voters and the Mercer Island City Council have previously rejected the levels of spending that would be necessary to restore all properties to native forest. The Open Space Vegetation Plan completed in 2004 proposes several levels of spending that could achieve minimum and intermediate levels of service to preserve some of the benefits of open space. Minimum levels of service would focus on removing ivy from trees. Intermediate levels of service would also remove invasive plants from areas that are not yet heavily invaded. Levels of service have been assigned according to priorities developed with input from two public meetings in June, 2004.

This plan proposes to utilize volunteer participation and neighborhood partnerships to implement significant portions of the plan. It provides an incentive for neighborhood leaders to recruit volunteers, grants and donations by offering equivalent plan implementation from the City. Priorities may shift as a result of this approach. The potential for this approach is unproven and may be limited by the staff time required to administer it. Dependent upon the levels of service selected for the prioritized sites, an investment of between $18,000 and $180,000 per year over a 20 year planning horizon would be required. The Plan recommends an annual City investment of $135,000 per year (2004 dollars). Since 2005, City Council has funded this plan at the higher level of service outlined in the plan.

The 2007-2008 Progress Report summarizes the third and fourth years of implementing the Mercer Island Open Space Vegetation Plan that was completed in 2004. Partnerships with the non-profit organizations EarthCorps and Mountains to Sound Greenway continued, while commercial landscape contractors were hired to accomplish the majority of the work plan. A combination of volunteer and contract crews removed invasive plants on 99.2 acres in 14 parks. Volunteers and contracted crews also planted a total of 2,407 trees and 2,066 shrubs. There were several significant differences in the program for the third and fourth years as compared to the second year. In the 2007-08 biennium, far more park acreage hosted comprehensive invasive removal projects (where all invasive plants were removed and new trees planted as needed) than in 2005-2006. While less acreage underwent selective projects (creating ivy survival rings around trees, inter-planting forested areas with young conifers, or treating holly and laurel with herbicide) during this biennium as compared to the previous, maintenance of past years’ project sites made up a significantly greater portion of the overall work for this biennium as compared to 2005-2006. The complexity of managing projects continued to increase as a greater portion of the overall work was accomplished by multiple contractors through small public works contracting.

Printable copy of the Open Space Vegetation Plan
Printable copy of the appendices to the Open Space Vegetation Plan
Printable copy of the Open Space Vegetation Progress Report for 2005
Printable copy of the Open Space Vegetation Progress Report for 2007-08