Deephaven planning commission recommends approval of two conditional-use permits for house additions

The Deephaven Planning Commission on Wednesday recommended city council approval of two conditional‑use permits for modest residential additions, concluding staff and the city engineer had reviewed and approved proposed stormwater mitigation plans.

Patrick, the planning staff member presenting both applications, told the commission the 3645 Parkway proposal would reduce net hard surface but nonetheless exceed the city’s 25% hard‑cover limit (reported at 32.14%). He said the project exceeds the limit by 947 square feet and requires 79 cubic feet of mitigation; an infiltration trench sized at 79.5 cubic feet was proposed and the city engineer had approved the grading and stormwater management plan.

Paul Chiu, director of engineering at Stambel 9 Design Build and the applicant’s representative, said the plan would collect roof runoff with downspouts piped to a subsurface system. "The net hard surface is decreasing," Chiu said, adding the proposed system is "more of a French drain style underground" and that "the net result is a drastic improvement in terms of net water leaving the site." Commissioners asked about trench location, whether multiple trenches had been considered, and tree preservation; staff and the applicant said the single trench is sized to capture the required volume and that tree impacts would be minimized where possible.

For 20240 Cottage Wood Avenue, Patrick said the proposed rear addition (254 square feet) raises hard‑cover from 32.42% to 33.1%, requiring 82 cubic feet of mitigation; the applicant proposed an infiltration trench sized to provide 86.4 cubic feet after the city’s 25% credit reduction. John Naylor of Revision Builders answered technical questions about lot lines, a proposed shed and a small fire ring, and confirmed the trench location would not intrude into the road right‑of‑way.

Commissioners discussed survey precision, how the city counts mitigation credit (the city’s approach gives 75% credit for some features), and whether the projects will materially change surface drainage. Several commissioners characterized the proposals as modest improvements to existing conditions and supported the staff recommendation.

Speaker 8 moved, and Speaker 2 seconded, that the planning commission accept staff findings and recommend city council approve the CUP for 3645 Parkway; the motion carried on a voice vote. The commission similarly moved to recommend approval for 20240 Cottage Wood Avenue and approved that recommendation by voice vote. Patrick told applicants both items would be before the city council on July 6 for final action.

The commission’s actions forward these items to the city council; the council will hold the hearings and make final determinations on the permits and related conditions.