King County Executive Dow Constantine has proposed renewing the county’s current parks levy, a plan he wants voters to approve before the levy runs out at the end of 2019.

The measure headed for the primary election ballot in August would, if passed, generate an estimated $738 million over the next six years to expand and connect 175 miles of regional trails, improve access to green space and recreation, and keep the county’s 200 parks clean, safe and open.

Among other things, the new funding would pay for designing and building crossings for trails over rivers and highways, adding parking at trailheads, replacing 11 ballfields, rehabilitating playground equipment in six parks, and maintaining park infrastructure such as pathways, roofs, fencing and electrical systems.

The money would come from assessments of 16 cents per $1,000 of assessed property value, which, for example, would cost the owner of a home valued at $500,000 about $7 per month. The latter is about $2 more than is currently connected.

The current levy, which voters approved in 2013, will expire Dec. 31. Voters have also approved the levy two other times since 2003.