The skies may have provided free irrigation for Fridley businesses in May, but someone has been making off with brass and copper parts from businesses' irrigation systems, according to Fridley police.

The Fridley Police Department issued this crime alert, dated "Spring of 2012":

Fridley Officers have received several reports indicating that unknown person(s) have removed irrigation valves, and supporting mechanical equipment from commercial properties. Typically irrigation valves and parts are made from Brass and/or Copper metal.

One example: In March, someone stole brass sprinklers valued at $10,000 from the "Landmark of Fridley" senior-citizen apartment building construction site in Fridley, according to police.

The crime alert continues:

Unfortunately, this type of theft has become very common. Commercial Properties with irrigation systems that include metal valves, piping, fittings or wiring become a tartet for this type of crime. The irrigation equipment is stolen and then sold to metal recyclers as scrap metal. Several commercial properties in Fridley have become victim to this type of crime.

The crime alert advises owners of commerical property to work with alarm companies to make sure vulnerable areas are covered.

It also asks people to report suspicious activiity immediately by calling 9-1-1.