MADRID - Spain's capacity to generate hydropower and irrigate crops rather than having to import gas and grain has soared to well above average levels, according to the latest official data on Tuesday.

Hydroelectric reservoirs held enough water to produce 11,860 gigawatt-hours, up 860 GWh from last week, the Ministry for the Environment and Rural Affairs said in a weekly bulletin.

With total demand for electricity logged by national grid operator REE running at 252,000 GWh a year, that would be enough by itself to supply the country for 17.2 average days.

Spain suffered a drought for most of 2009, but heavy rain since December has filled reservoirs to 15.8 percent above average levels for the past 10 years and boosted hydropower's share of the generation mix.

Gas-powered generators have meanwhile been producing less, which combined with slow demand for electricity has undermined consumption in Spain, which needs to import more than 99 percent of its gas.

Spain is also the world's third-largest importer of liquefied natural gas, via six regasification plants.

Abundant supplies of hydro together with booming output from wind parks have recently helped drive down wholesale electricity prices to all-time lows.

HEAVY RAIN

The Ministry meanwhile tallied rainfall that was 83 percent above the historical average (1930-96) at 26.6 millimeters.

That in turn was enough to fill reservoirs for consumption, including agricultural use, to 57.3 percent from 53.0 percent last week.

Crops such as maize need irrigation to grow in Spain's harsh climate and rain helps replenish ground water needed for non-irrigated wheat and barley.

Even with a bumper domestic crop, Spain needs to import at least 10 million tonnes of grain from origins as far afield as Argentina and Ukraine to meet demand.

Farmers say recent rain has been very good for crop growth and green shoots are now visible in the country's grain belt, but they estimate plantings may have dropped by 5 percent from last year due to low farm-gate prices.

Rice, cotton and alfalfa -- which is used in animal feed -- also need irrigation.

(Reporting by Martin Roberts; Editing by Keiron Henderson)