Finn Hill's Environmental Issues
Finn Hill’s history of logging, agricultural use, and suburban development has created a host of environmental issues that the Finn Hill Neighborhood Alliance is working to remedy. These challenges include:
Surface Water Management
Roads, houses, yards and other impermeable surfaces lead to heavy runoff of rainwater during storms that scours creek channels, erodes hillsides, and pollutes streams and, ultimately, Lake Washington. Creek water quality reports produced by the City of Kirkland indicate that the water quality of Finn Hill’s principal streams is adversely affected by high levels of nitrogen and phosphorus. An even greater problem may be the extent of runoff immediately after heavy storms. Impervious surfaces on Finn Hill create flashy waterflows that wash away fish habitat and prevent ground water from seeping into the soil and flowing into streams at a steady rate, so that they don’t dry up during the summer. Kirkland recently upgraded its surface water management plan to address some of these issues.
Covered with layers of glacial till, most of Finn Hill’s ravines and slopes present high risks of landslides and liquefaction. The City’s zoning code requires geotechnical studies before development occurs on particularly steep slopes. The Finn Hill Neighborhood Alliance commented on several aspects of the City’s recent revisions to its steep slope development regulations.
A healthy urban tree canopy is vital for clean air, cooler temperatures, surface water management, erosion control, and slope stability. Mature trees also support wildlife and enhance neighborhood character. Finn Hill’s tree canopy percentage was calculated in 2018 by the City of Kirkland at 50% - the highest of all Kirkland neighborhoods. Most of Finn Hill’s canopy cover is located in its parks and in ravines and in remaining large parcels that haven’t yet been developed to the capacity allowed by current zoning. As residential development – new construction and the addition of ADUs -- proceeds, Finn Hill’s tree cover will be reduced. The Finn Hill Neighborhood Alliance is working to mitigate canopy loss in three ways. First, it has advocated for stricter regulations governing tree removals and replacement planting associated with new development and road improvements. Second, it has advocated for more tree planting on public property. And, finally, it has focused on working with City and County officials to preserve woodlands through the expansion of the Finn Hill Green Loop.
More information about the issues outlined above can be found here:
Surface water management and stormwater runoff: Storm & Surface Water – City of Kirkland (kirklandwa.gov)
2023 surface water management plan: Stormwater Policies and Regulations – City of Kirkland (kirklandwa.gov)
Dashboards for the water quality of Finn Hill creeks: Kirkland Watersheds (arcgis.com)
Landslide risks: City of Kirkland Landslide Map (kirklandwa.gov)
Steep slope development regulations: KZC Chapter 85 – CRITICAL AREAS: GEOLOGICALLY HAZARDOUS AREAS (codepublishing.com)
2018 tree canopy survey: final-2018-utc-report.pdf (kirklandwa.gov)
Urban forest management plan: UFMPJuly2013_FINAL_DRAFT_08212013 (kirklandwa.gov)
Citywide tree code amendments: Tree Code Amendments – City of Kirkland (kirklandwa.gov)
Holmes Point overlay code (special tree retention regulations for Holmes Point): Holmes Point Overlay - Code Update – City of Kirkland (kirklandwa.gov)