LUBBOCK, Texas -- Beginning in July, the High Plains Underground Water Conservation District No. 1 precipitation enhancement program target area was expanded to include Curry and southwestern Quay Counties of New Mexico. Roosevelt County, New Mexico has been included in the cloud seeding target area since operations began May 31.
"Adding this extra area in New Mexico increases the precipitation enhancement target area from 8,440,790 acres to 9,818,500 acres," said A. Wayne Wyatt, High Plains Water District manager. "Residents in Curry County and southwestern Quay County will benefit from any additional rainfall generated as a result of the precipitation enhancement program. Seeding clouds in New Mexico will benefit producers within the High Plains Water District whose farms are close to the Texas-New Mexico line."
Participants pay a pro-rata share of the fixed and reimbursable program costs, based upon total acreage. The High Plains Water District will pay 70 percent of the program cost for its 6,869,910-acre service area. Roosevelt County will pay 16 percent of the cost for its 1,570,880-acre area; Curry County will pay nine percent of the cost for its 897,760 acres; and southwestern Quay County will pay five percent of the cost for its 479,950 acres.
The 75th Texas Legislature provided cost-share funding for precipitation enhancement within the state for the next biennium. As a result, it appears that the High Plains Water District will not have to increase taxes to fund the precipitation enhancement program for the next two years. "The water district's current tax rate is $0.0084 per $100 valuation. There should be very little variation between the current rate and the proposed 1998 tax rate to be set by the board of directors in August," said Wyatt.
The Water District is paying for the program's first year with operating fund reserves.
As of July 9, Weather Modification Inc. pilots have flown 23 cloud-seeding missions in an attempt to increase precipitation within the target area. One aircraft based in Amarillo and two in Lubbock dropped a total of 237 silver iodide flares into cloud systems within the target area from May 30 to July 9.
These aircraft have flown 16 days as of July 9. However there were 24 days when flight operations were suspended due to severe weather outbreaks or lack of seeding targets in the area.
As of July 10, the High Plains Water District has revised its "no-seed" order to include the southern half and northeast quarter of Lynn County; the southeastern three quarters of the eastern portion of Lubbock County; and all of Crosby County.
"The no-seed order is based upon a 10-day moving precipitation average. If an area received two or more inches of precipitation during the prior 10-day period, it is added to the no-seed order," said Wyatt. Areas receiving less than one-half inch of rain are priority areas. County Committee members in each of the 15 counties within the district also provide "seed or no-seed" advice for their respective precincts.
He added that cloud seeding operations do not take place whenever the National Weather Service issues a severe weather bulletin, such as a severe thunderstorm warning, flash flood warning, or tornado warning. Also, no seeding takes place if cloud tops reach 26,000 feet or more or if the pilot flies through the cloud system and finds it to be glaciated.
High Plains Water District officials are using a number of tools to determine the effectiveness of the cloud seeding missions.
"We are currently reviewing aircraft flight tracks printed on the target area map, printouts showing the latitude and longitude coordinates of each silver iodide flare dropped, and National Weather Service color maps showing where and how much precipitation occurred during the 24-hour period in which cloud seeding occurred.
In addition, computers capture images from the Littlefield radar site every 30 minutes. Water District personnel can put these images into motion using a looping program to see the position of clouds 30 minutes prior to aircraft launch and two hours after aircraft landing.
"All of these tools help us determine the effect from each cloud seeding mission," said Wyatt.
Water District staff will also review monthly and annual precipitation totals as collected in rain gauges at the 300 soil moisture monitoring sites maintained by the district. These rainfall data are then contoured and printed on a regional base map.
In addition, rainwater samples are being collected from at least six rain gauge sites for analysis to determine if silver iodide is present.
The precipitation enhancement program is scheduled to operate from May 15 to September 30, 1997.
Additional information about the 1997 precipitation enhancement program is available by contacting the High Plains Underground Water Conservation District No. 1, 2930 Avenue Q, Lubbock, TX 79405-1499, or by calling (806) 762-0181. Information is also available by accessing the water district's new web site at http://www.hub.ofthe.net/hpwd.
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