Just thinking, how about creating a small lake held back by a dam and power generator? the dam will provide power to electrical machines in a zone (e.g. the radar and...the radar). If the dam is destroyed, the radars in the zone will become disabled for 15 minutes (time outage can vary, i didnt want to sound ridiculous). This will be like a mini-HQ but only the field dar rings will be affected.
To keep with historical accuracy, Lancasters would fly with one bomb that was 50 inches in diameter, 60 inches long and weighed 9,250 lbs. Of this weight, 6,600 lbs was powerful RDX explosive. The bombers would have to fly at precisely 220 mph, 60 feet above the water and release the bomb about 425 yards from the dam wall. If not, then the bomb could roll short or bounce over the dam causing no damage.
Of course, the dam will be heavily defended using auto-ack and puffy ack. Again, there would only be one dam per zone and this would provide power needed to operate the field radar rings.
source:
http://www.historylearningsite.co.uk/dambusters.htm