Unpave LLC is the consulting practice of Aaron D. Clark, Ph.D., bringing fifteen years of Puget Sound ecosystem science, systems-level program design, and cross-sector coalition-building to environmental problems that are too tangled, too contested, or too under-resourced for any one sector to solve alone.
A scientist and program leader who has spent his career moving between the lab, the field, communities, and partners.
Aaron D. Clark, Ph.D. has spent the last fifteen years uplifting and accelerating green infrastructure, Native land return, ecological restoration, and adaptive management across the Puget Sound region. As Director of Strategic Partnerships and, before that, Green Infrastructure Program Manager at Stewardship Partners (2012–2023), he created and led the annual Green Infrastructure Summit of the Salish Sea and developed the Adopt-a-Downspout (Box of Rain) biofiltration program in partnership with WSDOT. He also directed the 12,000 Rain Gardens for Puget Sound campaign and built Sound Impacts, a map-based green infrastructure metrics portal that now tracks over 11,000 sites. He also led development of a regional bioretention monitoring protocol adopted across jurisdictions.
As E'lip Tilikum Operations Director at Na'ah Illahee Fund (2023–2026), he coordinated land protection planning with Tribal nations and Native-led organizations, advanced the integration of Traditional Ecological Knowledge into conservation strategy, and helped shape the capital and program plan for a $20 million Intertribal Traditional Ecological Knowledge center.
He holds a Ph.D. in Biology (Wildlife & Avian Biology) from the University of Washington and a B.A. in Biology from Reed College, and is the author of 25 peer-reviewed publications and a book chapter in Green New Cities of Tomorrow. He currently co-chairs the Seattle Urban Forestry Commission and serves on advisory bodies including the Green Equity Alliance Work Group, the Kitsap Forestry Working Group, and Western Washington University's Urban Planning and Sustainable Design Program.
Aaron founded Unpave LLC in 2025 to bring this same interdisciplinary, trust-based approach directly to clients, pairing rigorous ecological science with the relational, justice-centered practice built over two decades of work in the region.
Two examples of the systems-level problem-solving Unpave brings to a project. Both were developed during Aaron's time directing green infrastructure programs at Stewardship Partners.
Turning a stalled infrastructure problem into a community-led pilot
Polluted highway runoff is a serious, well-documented threat to salmon, including 6PPDQ, a tire-derived compound linked to fatal Urban Runoff Mortality Syndrome in returning coho. WSDOT was already balancing many competing priorities, from traffic safety to aging infrastructure, so Aaron worked closely with the agency from early on to design something that wouldn't compete for its limited bandwidth: a low-cost biofiltration planter box, installed and maintained by communities, fitted to the base of bridge downspouts. He partnered with engineers and researchers to refine the design, then spent several years building the collaborative relationship with WSDOT needed to pilot the concept together at the I-5 Ship Canal Bridge. Each box treats up to 250,000 gallons of stormwater a year and removes an average of 92% of 6PPDQ. The program, now called Adopt-a-Downspout, is owned and operated by Stewardship Partners and is expanding statewide.
Building a durable, cross-sector community of practice from scratch
Four years into directing green infrastructure programs at Stewardship Partners, Aaron saw a fragmented field: municipalities, businesses, academics, and nonprofits duplicating effort on a problem that was as cultural as it was technical. He convened a small coalition, then a cross-sector host committee, to launch an annual summit connecting the region's .com, .org, .gov, and .edu green infrastructure leaders. He deliberately distributed ownership of the event rather than holding it close, a decision that let his successors carry it forward smoothly when he moved on. Now in its second decade, the summit draws over 200 leaders a year and remains one of the region's key venues for cross-sector collaboration.
Unpave works with agencies, organizations, and landowners across four connected areas of practice, especially where a problem is technically complex, crosses sector lines, or has stalled for lack of a workable, right-sized solution.
Diagnosis and right-sized solution design for environmental problems that span sectors and jurisdictions: untangling the technical, institutional, and cultural pieces, then building the coalition needed to move a stalled idea into a working pilot.
Habitat restoration and long-range stewardship plans for farm, forest, riparian, marine shoreline, and urban sites, including residential, commercial, and industrial properties, from site assessment through planning, implementation, monitoring, and adaptive management. Includes forest planning support, drawn from direct experience managing working forest and shoreline land.
Program design, site assessment, monitoring protocols, comprehensive-plan integration, and ongoing maintenance for agencies and jurisdictions building out green stormwater infrastructure at scale.
Cross-sector facilitation, community engagement, and program and grant strategy, including science communication such as reports, grant writing, and public speaking, for coalitions and collaboratives. Particular strength in building shared ownership and distributed leadership into a program from the start, so it outlasts any one person.
Reciprocity, cultural humility, and Indigenous Traditional Ecological and Cultural Knowledge (ITECK) inform how all of this work gets done. As a white, non-Tribal practitioner, Aaron does not lead environmental justice or Land Back work; he brings that lens and relational grounding to his restoration and green infrastructure practice, and works in support of efforts led by Tribal nations and BIPOC colleagues.
Unpave exists to advance reciprocity between people and the land, and between people and each other.
Reversing dominance- and extraction-based relationships with the more-than-human world, for the sake of all people, all living beings, and Mother Earth.
Reversing dominance and extraction between humans (colonialism, racism, sexism, classism, white supremacy, homophobia, transphobia, capitalism) and advancing collective thriving. We all do better when we all do better.
Honoring ancestors, the living, and the yet to be born, as one continuous relationship of care and responsibility.
A future where everyone has a relationship with nature, community, and place in which reciprocity is centered and understood, where giving and receiving stay in dynamic balance.
Unpave supports agencies, organizations, businesses, and individuals working in green infrastructure, sustainable design, and habitat restoration. We build trust-based partnerships with our clients, because the challenging work of healing what is broken shouldn't leave anyone more isolated; it should be a chance to connect around shared values and goals.
Whether you're an agency, a Tribal nation, a nonprofit, or a landowner working through a restoration or equity challenge, I'd like to hear about it.