For the second year in a row, the biggest boating weekend of the season ended in relative quiet on Lake Minnetonka and other nearby lakes and rivers.

The Hennepin County Sheriff's Water Patrol — which monitors Lake Minnetonka, the Mississippi River and 105 other water bodies in the county — said deputies responded to six medical emergencies over the four-day holiday period, compared with 15 during a comparable four-day stretch in 2016 and 22 in a busy three-day stretch in 2015.

It appeared after Wednesday's annual cleanup near Big Island that there also was less trash littering the lake.

Even though incidents dropped, law enforcement authorities didn't let up on extra measures they had started last year. They continued to crack down on underage drinking and boating while intoxicated (BWI).

From Saturday through Tuesday, authorities cited 11 people for BWIs on Minnetonka and other west-metro lakes, compared with 14 arrests last year and one in 2015. They issued 45 minor consumption citations, compared with 50 last year and 18 in 2015.

Officials attribute the decline to additional education and proactive communication with boaters.

In 2015, a rowdy July 4th weekend sent authorities out on 75 emergency calls on Minnetonka, the metro area's biggest lake. Boaters packed the lake, and emergency crews struggled to get to victims.

That prompted intensified efforts last year, with more agencies and ambulances stationed near a new emergency dock. This year, six boats patrolled Minnetonka around the clock and two boats were on the Mississippi. No boating deaths were reported, although a toddler drowned in a Maple Grove pool.

Across Minnesota last weekend, authorities ramped up enforcement on the water, but the Department of Natural Resources didn't have results as of Wednesday. The state is on pace to record its deadliest year on waterways in years, with nine deaths so far.